Only build tokenizer database on linux

Change-Id: I85cae1c5c27f5c77ce12ceb0b77f147eb16c4016
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/sample_project/+/22922
Reviewed-by: Wyatt Hepler <hepler@google.com>
Commit-Queue: Anthony DiGirolamo <tonymd@google.com>
diff --git a/BUILD.gn b/BUILD.gn
index 277e191..617b5b8 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -56,6 +56,7 @@
     # build.
     deps += [ ":tests_run" ]
   }
+  deps += [ "$dir_pw_trace" ]
 }
 
 group("arduino") {
@@ -82,7 +83,11 @@
 
 pw_tokenizer_database("tokenizer_database") {
   database = "//source/tokenizer_database.csv"
-  targets = [ ":app(//targets/host:host_clang_debug)" ]
+  if (host_os == "linux") {
+    targets = [ ":app(//targets/host:host_clang_debug)" ]
+  } else {
+    targets = []
+  }
 
   if (dir_pw_third_party_arduino != "") {
     targets += [