Try to fix external_symbolizer_path.cpp test to stop breaking on buildbots.

Not sure what the issue is, but it might be because the test copies
llvm-symbolizer to a different directory, and it can't find libc++.
Try to add some REQUIRES that we use in other tests where we copy
llvm tools out of their original directories.

GitOrigin-RevId: 394913fdb96af1a8ab699140f23073f2f366f406
diff --git a/test/sanitizer_common/TestCases/external_symbolizer_path.cpp b/test/sanitizer_common/TestCases/external_symbolizer_path.cpp
index 118fdc9..7203ce0 100644
--- a/test/sanitizer_common/TestCases/external_symbolizer_path.cpp
+++ b/test/sanitizer_common/TestCases/external_symbolizer_path.cpp
@@ -1,3 +1,10 @@
+// If the binary looks up libraries using an rpath, we can't test this
+// without copying the whole lib dir or polluting the build dir.
+// REQUIRES: static-libs
+
+// The above also applies if the binary is built with libc++.
+// UNSUPPORTED: libcxx-used
+
 // REQUIRES: shell
 // REQUIRES: x86-target-arch
 // RUN: rm -rf %t.bin