[Bug c/91973] gcc failed for Multiple level macro expansion

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91973

--- Comment #3 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
Macro replacement for function-like macros is defined in C17 6.10.3.  
Note in paragraph 10 the words "the function-like macro name followed by a 
( as the next preprocessing token".  In your example foo ends up followed 
by ) not ( as the next preprocessing token.