[PATCH] Move LinkerInput to LinkingContext.

[Shankar Kalpathi Easwaran]

  With ELF the way that I plan to do is, for Linker script support is :-

  a) Recognize the file that its a linker script in the driver
  b) Add the options and extra input files to the InputGraph.
  c) Read the files in the driver as how it was.

  The way to do this in lld would be handle it in the Driver, recognize that the file has a directive section and add the input files that have been mentioned.

  The problem with this is TargetInfo has all the inputs again, which the InputGraph took it out.

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