[PATCH] [COMPILER-RT] Implement long double comparison functions

[GuanHong Liu]

  Hi Joerg

  Can I commit D2798, D2799, D2800, D2802, D2803, D2804 and D2805 ?
  These patches are also implemented for IEEE quad precision.

  Thanks,
  GuanHong

http://reviews.llvm.org/D2797

COMMIT
  http://reviews.llvm.org/rL205312