[Bug middle-end/38474] compile time explosion in dataflow_set_preserve_mem_locs at -O3

[jakub at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=38474

--- Comment #87 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
At least for PR92038 it is important to see CLOBBERs in the chain, including
the first position in there.