[asan] Enable back halt_on_error-torture.cc disabled on PowerPC.

Summary:
D33521 addressed a memory ordering issue in BlockingMutex, which seems
to be the cause of a flakiness of a few ASan tests on PowerPC.

Reviewers: eugenis

Subscribers: kubamracek, nemanjai, llvm-commits

Differential Revision: https://reviews.llvm.org/D33611

llvm-svn: 304045

compiler-rt/test/asan/TestCases/Posix/halt_on_error-torture.cc

@@ -18,10 +18,6 @@
 // RUN: %env_asan_opts=halt_on_error=false %run %t 10 20 >>20.txt 2>&1 || true
 // RUN: FileCheck --check-prefix=CHECK-COLLISION %s < 20.txt || FileCheck --check-prefix=CHECK-NO-COLLISION %s < 20.txt
 
-// UNSUPPORTED: powerpc64-unknown-linux-gnu
-// FIXME: This test regularly fails on powerpc64 BE.  Re-enable the test once
-// the problem(s) have been fixed.
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <pthread.h>