[PATCH] Move LinkerInput to LinkingContext.

[Shankar Kalpathi Easwaran]

  as it was discussed previously on llvmdev the plan is to remove inputfiles, linkerinput and merge it in filenode
  the resolver is going to traverse the inputgraph. this change will make new filenodes to be added at will.

  your change would make the change that I plan to make very hard. it is also not clean.

http://llvm-reviews.chandlerc.com/D1569