Add loongarch64 support

Copybara Import from https://github.com/bazelbuild/rules_cc/pull/723

BEGIN_PUBLIC
Add loongarch64 support (#723)

Closes #723
END_PUBLIC

Tested:
    TAP --sample ran all affected tests and none failed
    []
COPYBARA_INTEGRATE_REVIEW=https://github.com/bazelbuild/rules_cc/pull/723 from zhaixiaojuan:main 9be982fc933734b4e9884f2be2950fe1cb301aad
PiperOrigin-RevId: 947400739
Change-Id: Iff2a9bd2aee3c8e41755531e830e9ca49107bcdf

cc/private/toolchain/lib_cc_configure.bzl

diff --git a/cc/private/toolchain/lib_cc_configure.bzl b/cc/private/toolchain/lib_cc_configure.bzl
index 975dd44..4647003 100644
--- a/cc/private/toolchain/lib_cc_configure.bzl
+++ b/cc/private/toolchain/lib_cc_configure.bzl
@@ -257,6 +257,8 @@
         return "arm"
     if arch in ["aarch64"]:
         return "aarch64"
+    if arch in ["loongarch64"]:
+        return "loongarch64"
     return "k8" if arch in ["amd64", "x86_64", "x64"] else "piii"
 
 def is_cc_configure_debug(repository_ctx):