Fix Thumb2 function call isel. Thumb1 and Thumb2 should share the same
instructions for calls since BL and BLX are always 32-bit long and BX is always
16-bit long.

Also, we should be using BLX to call external function stubs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77756 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed