[Bug c++/103921] [modules] ICE dependent expression in explicit-specifier of instantiation of imported template

[johelegp at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103921

--- Comment #4 from Johel Ernesto Guerrero Peña <johelegp at gmail dot com> ---
For the above, when it's fixed:
```diff
-  explicit(B) operator int() const;
+  explicit(B) operator int() { return 0; }
```