[asan] Re-enable a test on i386-darwin.

This test has been reverted in r279918 due to flaky atos support in the OS
some machines in the buildbot fleet were running. This should not be a
problem anymore.

llvm-svn: 295766

compiler-rt/test/sanitizer_common/TestCases/symbolize_pc.cc

@@ -1,6 +1,5 @@
 // RUN: %clangxx -O0 %s -o %t
 // RUN: %env_tool_opts=strip_path_prefix=/TestCases/ %run %t 2>&1 | FileCheck %s
-// UNSUPPORTED: i386-darwin
 //
 // Tests __sanitizer_symbolize_pc.
 #include <stdio.h>