[X86][AVX] Added fast-isel intrinsics tests
[X86][AVX] Added fast-isel intrinsics tests

As discussed on PR24580, this patch adds some (more to come) initial fast-isel codegen tests to match the IR generated in clang/test/CodeGen/avx-builtins.c

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@261329 91177308-0d34-0410-b5e6-96231b3b80d8
(cherry picked from commit 38c5292f830899f793ba41c0f2b7723c0425f31e)

apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm,apple/swift-llvm