[Bug tree-optimization/90316] [8/9 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 #35 from Than McIntosh <thanm at google dot com> ---
I applied r271124 to the gcc-9 branch and re-ran the large testcase -- still
has the long compile time (2127 seconds), FWIW.