[Bug target/66821] reassoc-37.c fails on -march=pentium

[hjl.tools at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66821

--- Comment #5 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Yulia Koval from comment #4)
> The issue remains for -march=iamcu but not for -miamcu.

Let's fix -march=iamcu.