[MIPS]Multiple and add instructions for Mips are currently available in mips32r2/mips64r2 and later but should also be available in mips4, mips5, and mips64. This patch fixes the requested features and updates the corresponding test files.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230500 91177308-0d34-0410-b5e6-96231b3b80d8
14 files changed