Summary:
It is now the smallest superset for these ISA's.
FeatureMips4 now contains FeatureFPIdx since [ls][dw]xc1 were added in MIPS-IV.
Made the FPIdx feature bit lowercase so that it can be used in the -mattr option.
Depends on D3274
Reviewers: matheusalmeida
Reviewed By: matheusalmeida
Differential Revision: http://reviews.llvm.org/D3275
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205964 91177308-0d34-0410-b5e6-96231b3b80d8
