Specify a triple. MachO AArch64 support is missing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201335 91177308-0d34-0410-b5e6-96231b3b80d8
"foo" is not a ppc instruction, don't try to parse it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201336 91177308-0d34-0410-b5e6-96231b3b80d8
.file is only available on ELF, use a triple instead of -march.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201337 91177308-0d34-0410-b5e6-96231b3b80d8