Support matching signext attribute in the parallel_num_threads_codegen test to appease clang-cmake-mips builder.
Support matching signext attribute in the parallel_num_threads_codegen test to appease clang-cmake-mips builder.

The Mips target adds the signext attribute to signed 32-bit integers in order
to support the N32/N64 correctly. Integers must be promoted to 64-bit bit on
these ABI's.



git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@222618 91177308-0d34-0410-b5e6-96231b3b80d8

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