[Bug tree-optimization/77283] [7 Regression] Revision 238005 disables loop unrolling

[rdapp at linux dot vnet.ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77283

--- Comment #15 from rdapp at linux dot vnet.ibm.com ---
The updated patch fixes libquantum on s390 so PR77366 might indeed be to
simplified to check for that, but it was unrolled before r238005. Addressing
libquantum is more important, of course.