The 'CodeGenObjC/illegal-UTF8.m' get failed with Clang built with 32-bit targets...

The 'CodeGenObjC/illegal-UTF8.m' get failed with Clang built with 32-bit targets only (as example ARM-only) with the following error:

error: unable to create target: 'No available targets are compatible with triple "< ... any 64-bit target triple ... >"'

I didn't find any 64-bit dependencies for the test and I think removing '-m64' option should fix the problem and allow this test for any target specified by LLVM_DEFAULT_TARGET_TRIPLE.

Patch by Vlad Vereschaka.

Differential Revision: https://reviews.llvm.org/D61345

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@360005 91177308-0d34-0410-b5e6-96231b3b80d8