[Bug tree-optimization/86532] [9 Regression] Wrong code due to a wrong strlen folding starting with r262522

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86532

--- Comment #21 from Martin Sebor <msebor at gcc dot gnu.org> ---
Thanks for testing the patch!  I've tweaked it to avoid the ICE.  I'm not sure
what masked the ICE in my testing but mixing signed and unsigned types in the
same expression without conversion was the cause.