[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 #11 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
(The decl_function_context is probably redundant since I don't see how a
non-nested function could return VM type.)