[asan] adding support of 32-bit address sanitizer for MIPS

Summary: The patch supports both the clang cross-compiler and native compiler

Patch by Kumar Sukhani <Kumar.Sukhani@imgtec.com>

Test Plan:
Kumar had the following asan test results when compiled on a MIPS board:

  Expected Passes    : 96
  Expected Failures  : 2
  Unsupported Tests  : 84
  Unexpected Passes  : 4
  Unexpected Failures: 19

The list of unexpected failures can be found in the review.

Reviewers: kcc, petarj, dsanders

Reviewed By: kcc

Subscribers: farazs, kcc, llvm-commits

Differential Revision: http://reviews.llvm.org/D4208

llvm-svn: 211587