This converts a signed remainder instruction to unsigned remainder, which

This converts a signed remainder instruction to unsigned remainder, which
enables the code size optimisation to fold a rem and div into a single
aeabi_uidivmod call. This was not happening before because sdiv was converted
but srem not, and instructions with different signedness are not combined.

Differential Revision: http://reviews.llvm.org/D22214

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275403 91177308-0d34-0410-b5e6-96231b3b80d8