Revert of [libfuzzer] supporting libfuzzer on mac with asan

testing/libfuzzer/BUILD.gn

Index: testing/libfuzzer/BUILD.gn
diff --git a/testing/libfuzzer/BUILD.gn b/testing/libfuzzer/BUILD.gn
index 1ac14ecce3083cde5c0e56503938449d11590d05..2063f9206e2ce49ca5a2688030f0a8191fbcb543 100644
--- a/testing/libfuzzer/BUILD.gn
+++ b/testing/libfuzzer/BUILD.gn
@@ -37,16 +37,6 @@ static_library("libfuzzer_main") {
   }
 }
 
-# A config used by all fuzzer_tests.
-config("fuzzer_test_config") {
-  if (use_libfuzzer && is_mac) {
-    ldflags = [
-      "-Wl,-U,_LLVMFuzzerCustomMutator",
-      "-Wl,-U,_LLVMFuzzerInitialize",
-    ]
-  }
-}
-
 # Noop config used to tag fuzzer tests excluded from clusterfuzz.
 # Libfuzzer build bot uses this to filter out targets while
 # building an archive for clusterfuzz.