[Bug tree-optimization/90625] fold strcmp(a, b) == 0 to zero for strings of unequal but non-const lengths

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90625

--- Comment #2 from Martin Sebor <msebor at gcc dot gnu.org> ---
It looks like it might be possible by querying an EVRP instance for the range
of strinfo::nonzero_chars.  I have a working prototype for snprintf that should
be easily extensible to any other similar string built-in.