Added inst combine tarnsform for (1 << X) & C pattrens where C is (some PowerOf2 - 1)

This patch can handles following cases from http://nondot.org/sabre/LLVMNotes/InstCombine.txt
  "((1 << X) & 7) == 0" ==> "X > 2"
  "((1 << X) & 7) != 0" ==> "X < 3".

Differential Revision: http://reviews.llvm.org/D3678