https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121508
--- Comment #5 from Léo Hardt <leom.hardt at inf dot ufrgs.br> ---
For
int i = __has_include(<iostream
iostream would be essentially treated as an identifier:
crash2.cpp:1:11: error: ‘__has_include’ used outside of preprocessing directive
1 | int i = __has_include(<iostream
| ^~~~~
crash2.cpp:1:25: error: expected primary-expression before ‘<’ token
1 | int i = __has_include(<iostream
| ^
crash2.cpp:1:26: error: ‘iostream’ was not declared in this scope
1 | int i = __has_include(<iostream
| ^~~~
