Fix eabi calling convention when a 64 bit value shadows r3.

Without this what was happening was:

* R3 is not marked as "used"
* ARM backend thinks it has to save it to the stack because of vaarg
* Offset computation correctly ignores it
* Offsets are wrong

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110446 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed