[PATCH] [lld][ELF] Order segments properly

[Shankar Kalpathi Easwaran]

  This has to be reworked, and below is the approach.

  1) add the segment type to the key
  2) sort the segments
  3) pass1 : create all the segments as whatever it comes up with
  4) pass2: go and fix the PT_LOAD segment headers
  5) emit segment header information

http://llvm-reviews.chandlerc.com/D458