libsanitizer merge from upstream r173241

gcc/ChangeLog

gcc/config/darwin.h

libsanitizer/ChangeLog

libsanitizer/MERGE

libsanitizer/asan/asan_allocator.cc

libsanitizer/asan/asan_allocator.h

libsanitizer/asan/asan_allocator2.cc

libsanitizer/asan/asan_globals.cc

libsanitizer/asan/asan_intercepted_functions.h

libsanitizer/asan/asan_interceptors.cc

libsanitizer/asan/asan_internal.h

libsanitizer/asan/asan_linux.cc

libsanitizer/asan/asan_lock.h

libsanitizer/asan/asan_mac.cc

libsanitizer/asan/asan_malloc_mac.cc

libsanitizer/asan/asan_mapping.h

libsanitizer/asan/asan_new_delete.cc

libsanitizer/asan/asan_poisoning.cc

libsanitizer/asan/asan_rtl.cc

libsanitizer/asan/asan_stats.cc