[LoopIdiomRecognize] Turn two uncheck dyn_casts into regular casts.
[LoopIdiomRecognize] Turn two uncheck dyn_casts into regular casts.

These are casts on users of a PHINode to Instruction. I think since PHINode is an Instruction any users would also be Instructions. At least a cast will give us an assertion if its wrong.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@331498 91177308-0d34-0410-b5e6-96231b3b80d8

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