[PATCH] [MSan] [MIPS] Adding support for MIPS64

[Kostya Serebryany]

> I have one more query, is there is any plan to accept msan32?, if yes I will update whatever changes needed in http://reviews.llvm.org/D5672

msan on 32 bit will have very limited applicability due to limited address space. 
Remember, the application will have only < 1Gb of RAM available to it.
Supporting msan on 32-bit is an additional maintenance cost with little to not benefit, at least where I see it. 
Do you want msan on 32-bit because there are MIPS customers who really need it and can't use 64-bit, 
or just for completeness?

http://reviews.llvm.org/D5906