The C++ standard allows abstract parameters in deleted functions
and in function declarations
> The type of a parameter or the return type for a function definition
> shall not be a (possibly cv-qualified) class type that is
> incomplete or abstract within the function body
> unless the function is deleted.
Fixes https://github.com/llvm/llvm-project/issues/63012
Reviewed By: #clang-language-wg, aaron.ballman
Differential Revision: https://reviews.llvm.org/D152096
constructs that can do so into the initialization code. This fixes a number
of different cases in which we used to fail to check for abstract types.
Thanks to Tim Shen for inspiring the weird code that uncovered this!
llvm-svn: 289753
