[Bug c/70093] Instancing function with VM return type cases internal compiler error in 'assign_stack_temp_for_type'.

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70093

--- Comment #6 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Ugh, a combination of a nested function and a VLA-in-a-struct.

We're trying to allocate variable-sized temporary.  Guess that's a wrong thing
to do, we should generate __builtin_alloca or __builtin_alloca_with_align when
expanding the call.