[AVX-512] Integrate mask register copying more completely into X86InstrInfo::copyPhysReg and simplify. No functional change intended.
[AVX-512] Integrate mask register copying more completely into X86InstrInfo::copyPhysReg and simplify. No functional change intended.

The code is now written in terms of source and dest classes with feature checks inside each type of copy instead of having separate functions for each feature set.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@280673 91177308-0d34-0410-b5e6-96231b3b80d8

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