[mips] Handle 64 bit immediate in and/or/xor pseudo instructions on mips64

Previously LLVM was assuming 32-bit signed immediates which results in and with
a bitmask that has bit 31 set to incorrectly include bits 63-32 in the result.
After applying this patch I can now compile all of the FreeBSD mips assembly
code with clang.

This issue also affects the nor, slt and sltu macros and I will fix those in a
separate review.

Patch By: Alexander Richardson

Commit message reformatted by sdardis.

Reviewers: atanasyan, theraven, sdardis

Differential Revision: https://reviews.llvm.org/D30298

llvm-svn: 296125