[X86] Remove unnecessary peekThroughEXTRACT_SUBVECTORs call.
[X86] Remove unnecessary peekThroughEXTRACT_SUBVECTORs call.

The GetSplatValue/IsSplatVector call will call this anyhow and the later code is just for a v2i64 type so doesn't need it.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@348253 91177308-0d34-0410-b5e6-96231b3b80d8

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