[X86] Remove invalid code from LowerVSELECT.
[X86] Remove invalid code from LowerVSELECT.

This code attempted to say that v8i16/v16i16 VSELECT is legal if BWI and VLX are enabled, but the only way we could reach this point is if the condition was not a vXi1 type. Which means it really wasn't legal.

We don't have any tests that exercise this code. So I'm hoping it wasn't really reachable.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@316851 91177308-0d34-0410-b5e6-96231b3b80d8

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