DebugInfo: Keep track of subprograms who's arguments have been promoted.
Matching behavior with DeadArgumentElimination (and leveraging some
now-common infrastructure), keep track of the function from debug info
metadata if arguments are promoted.
This may produce interesting debug info - since the arguments may be
missing or of different types... but at least backtraces, inlining, etc,
will be correct.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212128
91177308-0d34-0410-b5e6-
96231b3b80d8