[X86] Remove redundant bitcast patterns for 128/256-bit vectors. These only differ from the SSE/AVX versions by the register class, but register class has no bearing on isel.
[X86] Remove redundant bitcast patterns for 128/256-bit vectors. These only differ from the SSE/AVX versions by the register class, but register class has no bearing on isel.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@271623 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm