headers: add missing Windows ARM Interlocked intrinsics
headers: add missing Windows ARM Interlocked intrinsics

On ARM, there are multiple versions of each of the intrinsics, with
acquire/relaxed/release barrier semantics.

The newly added ones are provided as inline functions here instead of builtins,
since they should only be available on certain archs (arm/aarch64).

This is necessary in order to compile C++ code for ARM in MSVC mode.

Patch by Martin Storsjö!

git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@282447 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang