[PATCH] [TargetInfo] Move LinkerInputFile to TargetInfo and rename more specific name

[Rui Ueyama]

  Adding Michael and Nick to get their inputs.

  Shankar, I'm not still sure if we are on the same page. I don't want TargetInfo to create flavor-specific atoms too.

  If you want to add a target specific atom to a linker internal file, you can define a new class in ELF directory independently from this change, instantiate it in ELFTargetInfo, and add it to the LinkerInput. Generic TargetInfo will add another linker internal file (of class SimpleFile which is different from yours) to LinkerInput by this change, but you don't need to find that linker internal file instance. You can just add a new linker internal file file of your own class to LinkerInput. As a result, LinkerInput will have two pseudo files, one is added by TargetInfo for "-u" and the other is by ELFTargetInfo for the feature you want to add. They will serve their purpose independent from each other.

http://llvm-reviews.chandlerc.com/D1016