[LV] Use BB::instructionsWithoutDebug to skip DbgInfo (NFC).
[LV] Use BB::instructionsWithoutDebug to skip DbgInfo (NFC).

This patch updates some code responsible the skip debug info to use
BasicBlock::instructionsWithoutDebug. I think this makes things
slightly simpler and more direct.

Reviewers: mkuper, rengolin, dcaballe, aprantl, vsk

Reviewed By: rengolin

Differential Revision: https://reviews.llvm.org/D46254


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@331174 91177308-0d34-0410-b5e6-96231b3b80d8

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