Redo part of r127137:
Pass down the correct C->getArgs, but keep it with the original
DerivedArgList type. Slightly adjust the MakeIndex call for the
different base type. This unbreaks the handling of --no-mangle on Darwin.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@127142 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed