https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110340
--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Full testcase for the first 2 issues raised in the paper:
```
int \\
u\
0\
3\
9\
1 = 0;
#define CONCAT(x,y) x##y
int CONCAT(\,u0393)=0;
```
Testcase for the last one:
```
const char * foo=" // { dg-error "" }
```
as far as I understand from the paper, instead of the above being undefined at
compiletime, the first testcase becomes valid and the last one becomes invalid.
And right now GCC acts according to the paper already so there is not anything
to be done. Maybe add a testcase for these if there is not already one is
enough ...
