[MIPS GlobalISel] Add floating point register bank

Add floating point register bank for MIPS32.
Implement getRegBankFromRegClass for float register classes.

Differential Revision: https://reviews.llvm.org/D59643


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356883 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed