Check if there are uninitialized M when quick return in ?LARR?

[langou]

In #769 , @akobotov fixes an issue for DLARRD and SLARRD introduced with 16db9c2 .

@akobotov mentions that the issue might be present in other ?LARR? subroutines.

I agree that this is possible. It would be good to check.

Request for help: can someone check? if no issue, can you report "no issue"? if issue, can you provide a PR?

[echeresh]

It was my commit originally. Sorry for leaving the bug that went undetected for 5 years :)
I carefully reviewed the other sources but haven't found any similar spots with double quick return so I think the issue can be closed.

[langou]

Thanks @echeresh for checking!