[x86] Add an AVX run to the 128-bit v2 tests, teach them to have a generic SSE and AVX mode in addition to a specific AVX1 test path, and flesh out the AVX tests.
[x86] Add an AVX run to the 128-bit v2 tests, teach them to have
a generic SSE and AVX mode in addition to a specific AVX1 test path, and
flesh out the AVX tests.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@218192 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,dslab-epfl/asap,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,apple/swift-llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,dslab-epfl/asap,GPUOpen-Drivers/llvm,dslab-epfl/asap,llvm-mirror/llvm,apple/swift-llvm,dslab-epfl/asap,dslab-epfl/asap