The gfc_match_select_rank issue showed up in the testsuite
and was found by Martin's asan-bootstrapped GCC. First
analysis by Harald – thanks to both!

However, I think the other variables I fixed were also
prone to overflows; see below for its usage.

OK for mainline? Other branches?

Tobias

PS: Other pending Fortran patches – please review!
[Patch] Fortran: Fix intrinsic null() handling [PR99651]
[Patch] Fortran: Fix func decl mismatch [PR93660]

PPS: Usage of 'name' in the patched functions:

resolve_select_type (gfc_code *code, gfc_namespace *old_ns)
   char name[GFC_MAX_SYMBOL_LEN];
...
         sprintf (name, "__tmp_class_%s", c->ts.u.derived->name);


select_intrinsic_set_tmp (gfc_typespec *ts)
{
   char name[GFC_MAX_SYMBOL_LEN];
...
         sprintf (name, "__tmp_class_%s", ts->u.derived->name);


gfc_match_select_type (void)
...
   char name[GFC_MAX_SYMBOL_LEN];
...
   m = gfc_match (" %n => %e", name, &expr2);

gfc_match_select_rank (void)
...
   char name[GFC_MAX_SYMBOL_LEN];
...
   m = gfc_match (" %n => %e", name, &expr2);