InstCombine: Fix a crash in Descale for multiply-by-zero

Fix a crash in `InstCombiner::Descale()` when a multiply-by-zero gets
created as an argument to a GEP partway through an iteration, causing
-instcombine to optimize the GEP before the multiply.

rdar://problem/17615671

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212742 91177308-0d34-0410-b5e6-96231b3b80d8
Make it possible for the Subtarget to change between function
passes in the mips back end. This, unfortunately, required a
bit of churn in the various predicates to use a pointer rather
than a reference.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212744 91177308-0d34-0410-b5e6-96231b3b80d8
Add the CSR company and the Kalimba DSP processor to Triple.

Patch by Matthew Gardiner with fixes by me.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212745 91177308-0d34-0410-b5e6-96231b3b80d8