Build llvm-symbolizer when building Clang.
Run the tests with LLVM_SYMBOLIZER_PATH set (to use llvm-symbolizer)
Run the tests with ASAN_OPTIONS=strict_memcmp=0 (to work around http://crbug.com/178677 and http://crbug.com/178404)


git-svn-id: http://address-sanitizer.googlecode.com/svn/trunk@1646 3c3640eb-14a6-2bb8-0b94-e9e73afe33f5