[Clang] Fix coroutine promise with inherited allocation functions (#179141)
The compiler frontend crashed when the promise class overloads operator
new/delete without a regular function declaration. This happens when the
promise class derives from a base class and takes the allocation
functions from the base class with:
using Base::operator new;
using Base::operator delete;
This was initially introduced by
1cd59264aa2fb4b0ba70ff03c1298b1b5c21271e.
This should also fix #164088