[block-freq] Add a print method on BlockFrequencyImpl for printing block frequencies and a convenience method for the common case of getting/printing a basic block.
[block-freq] Add a print method on BlockFrequencyImpl for printing block frequencies and a convenience method for the common case of getting/printing a basic block.

BlockFrequencies can only be printed relative to their entry frequency. Thus
since the entry frequency is no longer necessarily a static constant on the
BlockFrequency class and is instead a potentially dynamic value taken from
BlockFrequencyImpl, we must necessarily print it via a method on
BlockFrequencyImpl.

git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@197285 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-llvm,llvm-mirror/llvm,chubbymaggie/asap,GPUOpen-Drivers/llvm,chubbymaggie/asap,chubbymaggie/asap,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,llvm-mirror/llvm,dslab-epfl/asap,apple/swift-llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,chubbymaggie/asap,GPUOpen-Drivers/llvm,GPUOpen-Drivers/llvm,apple/swift-llvm,apple/swift-llvm,GPUOpen-Drivers/llvm,llvm-mirror/llvm,llvm-mirror/llvm,llvm-mirror/llvm,chubbymaggie/asap,dslab-epfl/asap,dslab-epfl/asap,dslab-epfl/asap,chubbymaggie/asap,llvm-mirror/llvm,dslab-epfl/asap,apple/swift-llvm,dslab-epfl/asap,llvm-mirror/llvm,llvm-mirror/llvm,GPUOpen-Drivers/llvm,dslab-epfl/asap,apple/swift-llvm