Use simpler version of sys::fs::exists. NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217618 91177308-0d34-0410-b5e6-96231b3b80d8
[MCJIT] Add support for ARM HALF_DIFF relocations to MCJIT.

Fixes <rdar://problem/18297804>.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217620 91177308-0d34-0410-b5e6-96231b3b80d8