Revert Thumb-2 conversion of some ARM builtins.

The udivmodsi4/modsi3/umodsi3 code computes jump targets based on ARM encodings
(if CLZ is present and IDIV is not present).

Reverts parts of r211032 and r211035.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@213309 91177308-0d34-0410-b5e6-96231b3b80d8