[Bug tree-optimization/90316] [8/9/10 Regression] large compile time increase in opt / alias stmt walking for Go example

[thanm at google dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90316

--- Comment #7 from Than McIntosh <thanm at google dot com> ---
I patched in your change and reran the original testacse. Verified that this
fixes the problem, compile time now down to ~8 seconds.  Thank you for the very
quick turnaround-- much appreciated.