[PATCH, AVR] Fix PR target/50925, use hard_frame_pointer_rtx

[Georg-Johann Lay]

Denis Chertykov wrote:
> Hi Georg.
> 
> I have found that conversion AVR port to using hard_frame_pointer have
> resolved PR 50925 .
> I have tested the patch without regressions, but I'm worry about it.
> Can you test it with your testsuite for regressions ?
> May be you have your own special difficult tests (special for addressing) ?

Hi Denis.

My test suite is plain vanilla, there are no special test cases that are not
upstream. So you should get the same test results.