[X86] getExtendInVec - take a ISD::*_EXTEND opcode instead of a IsSigned bool flag. NFCI.
[X86] getExtendInVec - take a ISD::*_EXTEND opcode instead of a IsSigned bool flag. NFCI.

Prep work to support ANY_EXTEND/ANY_EXTEND_VECTOR_INREG without needing another flag.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@363818 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm