ARMFrameLowering: Reserve emergency spill slot for large arguments

We need to reserve an emergency spill slot in cases with large argument
types that could overflow immediate offsets for FP relative address
calculations.

rdar://31317893

Differential Revision: https://reviews.llvm.org/D31643

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300639 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed