[PATCH] [Compiler-rt][Sanitizer][MSan][MIPS] Adding support for MIPS32

[Mohit Bhakkad]

>>! In D5672#10, @eugenis wrote:
> What's the overall status of this work? Proper support of a new platform (and a new bitness) would require a lot more changes than this. If you have a larger patch, please upload it here for a general discussion.

I have tried to change every architecture specific code as per my understanding, please suggest on anything we missed out.
Below are the test results on mips32 board:

19 test cases are failing out of 88:
  - 3 are x86_64 specific
  - 2 are working after changing addresses in program(64--->32)
  - 9 are failing because of minor differences with expected o/p
  - I am working on remaining 5 failing tests.

I am going to submit a separate patch for testing related changes.

http://reviews.llvm.org/D5672