[NFC][FunctionAttrs] Remove duplication in old/new PM pipeline
[NFC][FunctionAttrs] Remove duplication in old/new PM pipeline

This patch just extract code into a separate function to remove some
duplication between the old and new pass manager pipeline. Due to the
different CGSCC iterators used, not all code duplication was eliminated.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@338585 91177308-0d34-0410-b5e6-96231b3b80d8

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