[mips] Add the capability to search delay slot filling instructions in
successor basic blocks.

Currently this is off by default.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176329 91177308-0d34-0410-b5e6-96231b3b80d8
[mips] Remove unused option. Fix 80-column violations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176330 91177308-0d34-0410-b5e6-96231b3b80d8