The method is called "get *Param* Alignment", and is only used for
return values exactly once, so it should take argument indices, not
attribute indices.
Avoids confusing code like:
IsSwiftError = CS->paramHasAttr(ArgIdx, Attribute::SwiftError);
Alignment = CS->getParamAlignment(ArgIdx + 1);
Add getRetAlignment to handle the one case in Value.cpp that wants the
return value alignment.
This is a potentially breaking change for out-of-tree backends that do
their own call lowering.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301682 91177308-0d34-0410-b5e6-96231b3b80d8
52b0228949