To make this stick, I've disallowed direct use of that overload of
CreateCall. I've left the Constant overloads available, but eventually
we might want to consider fixing those, too, just to get all of this
code out of the business of manually remembering to pass around
attributes and calling conventions.
The test changes reflect the fact that we weren't really setting
attributes consistently at all, in this case on value witnesses.
The merge in 5f02db4d3e had a bunch of conflicts. I fixed a few references
to llvm::AttributeSet that needed to be llvm::AttributeList but I missed
this one.
The goals here are four-fold:
- provide cleaner internal abstractions
- avoid IR bloat from extra bitcasts
- avoid recomputing function-type lowering information
- allow more information to be propagated from the function
access site (e.g. class_method) to the call site
Use this framework immediately for class and protocol methods.