Switch native_binary/test to use symlinks (#340)

A copy should not be necessary here. The symlink action falls back to
copying when symlinks are not enabled on windows, which I think would 
be the only problem with using symlinks:
https://docs.bazel.build/versions/4.2.2/command-line-reference.html#flag--windows_enable_symlinks
diff --git a/docs/native_binary_doc.md b/docs/native_binary_doc.md
index 1a330ca..a9c476d 100755
--- a/docs/native_binary_doc.md
+++ b/docs/native_binary_doc.md
@@ -5,7 +5,7 @@
 These rules let you wrap a pre-built binary or script in a conventional binary
 and test rule respectively. They fulfill the same goal as sh_binary and sh_test
 do, but they run the wrapped binary directly, instead of through Bash, so they
-don't depend on Bash and work with --shell_exectuable="".
+don't depend on Bash and work with --shell_executable="".
 
 
 <a id="#native_binary"></a>
@@ -13,24 +13,25 @@
 ## native_binary
 
 <pre>
-native_binary(<a href="#native_binary-name">name</a>, <a href="#native_binary-src">src</a>, <a href="#native_binary-out">out</a>, <a href="#native_binary-data">data</a>, <a href="#native_binary-kwargs">kwargs</a>)
+native_binary(<a href="#native_binary-name">name</a>, <a href="#native_binary-data">data</a>, <a href="#native_binary-out">out</a>, <a href="#native_binary-src">src</a>)
 </pre>
 
+
 Wraps a pre-built binary or script with a binary rule.
 
-You can "bazel run" this rule like any other binary rule, and use it as a tool in genrule.tools for example. You can also augment the binary with runfiles.
+You can "bazel run" this rule like any other binary rule, and use it as a tool
+in genrule.tools for example. You can also augment the binary with runfiles.
 
 
-**PARAMETERS**
+**ATTRIBUTES**
 
 
-| Name  | Description | Default Value |
-| :------------- | :------------- | :------------- |
-| <a id="native_binary-name"></a>name |  The name of the rule.   |  none |
-| <a id="native_binary-src"></a>src |  label; path of the pre-built executable   |  none |
-| <a id="native_binary-out"></a>out |  output; an output name for the copy of the binary. (Bazel requires that this rule make a copy of 'src'.)   |  none |
-| <a id="native_binary-data"></a>data |  list of labels; data dependencies   |  <code>None</code> |
-| <a id="native_binary-kwargs"></a>kwargs |  The &lt;a href="https://docs.bazel.build/versions/main/be/common-definitions.html#common-attributes-binaries"&gt;common attributes for binaries&lt;/a&gt;.   |  none |
+| Name  | Description | Type | Mandatory | Default |
+| :------------- | :------------- | :------------- | :------------- | :------------- |
+| <a id="native_binary-name"></a>name |  A unique name for this target.   | <a href="https://bazel.build/docs/build-ref.html#name">Name</a> | required |  |
+| <a id="native_binary-data"></a>data |  data dependencies. See https://docs.bazel.build/versions/main/be/common-definitions.html#typical.data   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
+| <a id="native_binary-out"></a>out |  An output name for the copy of the binary   | String | required |  |
+| <a id="native_binary-src"></a>src |  path of the pre-built executable   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | required |  |
 
 
 <a id="#native_test"></a>
@@ -38,24 +39,24 @@
 ## native_test
 
 <pre>
-native_test(<a href="#native_test-name">name</a>, <a href="#native_test-src">src</a>, <a href="#native_test-out">out</a>, <a href="#native_test-data">data</a>, <a href="#native_test-kwargs">kwargs</a>)
+native_test(<a href="#native_test-name">name</a>, <a href="#native_test-data">data</a>, <a href="#native_test-out">out</a>, <a href="#native_test-src">src</a>)
 </pre>
 
+
 Wraps a pre-built binary or script with a test rule.
 
-You can "bazel test" this rule like any other test rule. You can also augment the binary with
-runfiles.
+You can "bazel test" this rule like any other test rule. You can also augment
+the binary with runfiles.
 
 
-**PARAMETERS**
+**ATTRIBUTES**
 
 
-| Name  | Description | Default Value |
-| :------------- | :------------- | :------------- |
-| <a id="native_test-name"></a>name |  The name of the test rule.   |  none |
-| <a id="native_test-src"></a>src |  label; path of the pre-built executable   |  none |
-| <a id="native_test-out"></a>out |  output; an output name for the copy of the binary. (Bazel requires that this rule make a copy of 'src'.)   |  none |
-| <a id="native_test-data"></a>data |  list of labels; data dependencies   |  <code>None</code> |
-| <a id="native_test-kwargs"></a>kwargs |  The &lt;a href="https://docs.bazel.build/versions/main/be/common-definitions.html#common-attributes-tests"&gt;common attributes for tests&lt;/a&gt;.   |  none |
+| Name  | Description | Type | Mandatory | Default |
+| :------------- | :------------- | :------------- | :------------- | :------------- |
+| <a id="native_test-name"></a>name |  A unique name for this target.   | <a href="https://bazel.build/docs/build-ref.html#name">Name</a> | required |  |
+| <a id="native_test-data"></a>data |  data dependencies. See https://docs.bazel.build/versions/main/be/common-definitions.html#typical.data   | <a href="https://bazel.build/docs/build-ref.html#labels">List of labels</a> | optional | [] |
+| <a id="native_test-out"></a>out |  An output name for the copy of the binary   | String | required |  |
+| <a id="native_test-src"></a>src |  path of the pre-built executable   | <a href="https://bazel.build/docs/build-ref.html#labels">Label</a> | required |  |
 
 
diff --git a/rules/BUILD b/rules/BUILD
index c1ffbf2..e2709d6 100644
--- a/rules/BUILD
+++ b/rules/BUILD
@@ -41,7 +41,6 @@
 bzl_library(
     name = "native_binary",
     srcs = ["native_binary.bzl"],
-    deps = ["//rules/private:copy_file_private"],
 )
 
 bzl_library(
diff --git a/rules/native_binary.bzl b/rules/native_binary.bzl
index a3f0d73..a027fc9 100644
--- a/rules/native_binary.bzl
+++ b/rules/native_binary.bzl
@@ -17,17 +17,16 @@
 These rules let you wrap a pre-built binary or script in a conventional binary
 and test rule respectively. They fulfill the same goal as sh_binary and sh_test
 do, but they run the wrapped binary directly, instead of through Bash, so they
-don't depend on Bash and work with --shell_exectuable="".
+don't depend on Bash and work with --shell_executable="".
 """
 
-load("//rules/private:copy_file_private.bzl", "copy_bash", "copy_cmd")
-
-def _impl_rule(ctx, is_windows):
+def _impl_rule(ctx):
     out = ctx.actions.declare_file(ctx.attr.out)
-    if is_windows:
-        copy_cmd(ctx, ctx.executable.src, out)
-    else:
-        copy_bash(ctx, ctx.executable.src, out)
+    ctx.actions.symlink(
+        target_file = ctx.executable.src,
+        output = out,
+        is_executable = True,
+    )
     runfiles = ctx.runfiles(files = ctx.files.data)
 
     # Bazel 4.x LTS does not support `merge_all`.
@@ -48,9 +47,6 @@
         runfiles = runfiles,
     )
 
-def _impl(ctx):
-    return _impl_rule(ctx, ctx.attr.is_windows)
-
 _ATTRS = {
     "src": attr.label(
         executable = True,
@@ -60,70 +56,37 @@
         allow_files = True,
         mandatory = True,
         cfg = "target",
+        doc = "path of the pre-built executable",
     ),
-    "data": attr.label_list(allow_files = True),
+    "data": attr.label_list(
+        allow_files = True,
+        doc = "data dependencies. See" +
+              " https://docs.bazel.build/versions/main/be/common-definitions.html#typical.data",
+    ),
     # "out" is attr.string instead of attr.output, so that it is select()'able.
-    "out": attr.string(mandatory = True),
-    "is_windows": attr.bool(mandatory = True),
+    "out": attr.string(mandatory = True, doc = "An output name for the copy of the binary"),
 }
 
-_native_binary = rule(
-    implementation = _impl,
+native_binary = rule(
+    implementation = _impl_rule,
     attrs = _ATTRS,
     executable = True,
+    doc = """
+Wraps a pre-built binary or script with a binary rule.
+
+You can "bazel run" this rule like any other binary rule, and use it as a tool
+in genrule.tools for example. You can also augment the binary with runfiles.
+""",
 )
 
-_native_test = rule(
-    implementation = _impl,
+native_test = rule(
+    implementation = _impl_rule,
     attrs = _ATTRS,
     test = True,
+    doc = """
+Wraps a pre-built binary or script with a test rule.
+
+You can "bazel test" this rule like any other test rule. You can also augment
+the binary with runfiles.
+""",
 )
-
-def native_binary(name, src, out, data = None, **kwargs):
-    """Wraps a pre-built binary or script with a binary rule.
-
-    You can "bazel run" this rule like any other binary rule, and use it as a tool in genrule.tools for example. You can also augment the binary with runfiles.
-
-    Args:
-      name: The name of the rule.
-      src: label; path of the pre-built executable
-      out: output; an output name for the copy of the binary. (Bazel requires that this rule make a copy of 'src'.)
-      data: list of labels; data dependencies
-      **kwargs: The <a href="https://docs.bazel.build/versions/main/be/common-definitions.html#common-attributes-binaries">common attributes for binaries</a>.
-    """
-    _native_binary(
-        name = name,
-        src = src,
-        out = out,
-        data = data,
-        is_windows = select({
-            "@bazel_tools//src/conditions:host_windows": True,
-            "//conditions:default": False,
-        }),
-        **kwargs
-    )
-
-def native_test(name, src, out, data = None, **kwargs):
-    """Wraps a pre-built binary or script with a test rule.
-
-    You can "bazel test" this rule like any other test rule. You can also augment the binary with
-    runfiles.
-
-    Args:
-      name: The name of the test rule.
-      src: label; path of the pre-built executable
-      out: output; an output name for the copy of the binary. (Bazel requires that this rule make a copy of 'src'.)
-      data: list of labels; data dependencies
-      **kwargs: The <a href="https://docs.bazel.build/versions/main/be/common-definitions.html#common-attributes-tests">common attributes for tests</a>.
-    """
-    _native_test(
-        name = name,
-        src = src,
-        out = out,
-        data = data,
-        is_windows = select({
-            "@bazel_tools//src/conditions:host_windows": True,
-            "//conditions:default": False,
-        }),
-        **kwargs
-    )