use a symlink instead of replacing

Author: keith

clang_tidy/clang_tidy_test.bzl

@@ -7,7 +7,7 @@ load(":clang_tidy.bzl", "deps_flags", "is_c_translation_unit", "rule_sources", "
 # Tests run with a different directory structure than normal compiles. This
 # fixes up include paths or any other arguments that are sensitive to this
 def _fix_argument_path(ctx, arg):
-    return arg.replace(ctx.bin_dir.path, ".").replace("external/", "../")
+    return arg.replace(ctx.bin_dir.path, ".")
 
 def _get_copts_attr(ctx, copts_attr):
     copts = []
@@ -53,6 +53,8 @@ if [[ ! -f .clang-tidy ]]; then
   exit 1
 fi
 
+ln -s .. external
+
 has_srcs=false
 if [[ -n "{c_sources}" ]]; then
   "$bin" --quiet {c_sources} -- {c_flags}