[TSan][libdispatch] Turn ignore_noninstrumented_modules=1 back on for Darwin

llvm-svn: 358208

Author: yln

compiler-rt/test/tsan/libdispatch/lit.local.cfg

@@ -12,3 +12,6 @@ if 'libdispatch' in root.available_features:
       config.substitutions[index] = (template, replacement + additional_cflags)
 else:
   config.unsupported = True
+
+if config.host_os == 'Darwin':
+  config.environment['TSAN_OPTIONS'] += ':ignore_noninstrumented_modules=1'