emulators/qemu-user-static{,-devel}: pull in recent syscall fixes/additions

[kevans]

Summary

emulators/qemu-user-static{,-devel}: pull in recent syscall fixes/additions

This implements (for -CURRENT hosts):
- __realpathat(2)
- shm_open2(2)
- shm_rename(2)
- close_range(2)
- fcntls for file sealing

Some other improvements:
- Fixed SHM_ANON to actually work under qemu-user-static
- Incorporate @dim's fix for the configure script
- Fixes another possible source of hanging threads

These two ports will not normally be updated simultaneously like this to
the same version; the next qemu-user-static-devel (rebase forward past 3.1)
is still in the preparation stage.  In the meantime, update it to at least
not be older than the production-quality qemu-user-static.

Approved by:	koobs (mentor) or bapt (mentor)
Differential_Revision:	<< this one >>

Test Plan

Q/A:

• portlint (looks fine.)
• testport (all amd64: 11.3, 12.1, -CURRENT)

[koobs]

Missing MFH: <branch|No> <reason> and Approved by:

[darkfiberiru_gmail.com]

I've tested these changes and have seen issues with unmapped syscalls fixed allowing me to do poudriere cross builds again.

[darkfiberiru_gmail.com]

@kevans
Just a friendly ping

[koobs]

@kevans is now the maker of his own fortune as of rP542829

I apart from non explicit MFH in commit log message, I otherwise approve