Problem with /boot/loader in 11.3-PRERELEASE r347946

[Cyrus Rahman]

I've just updated to r347946 from r344695.  Upon booting the loader, I get:

panic: free: guard2 fail @ 0xcd8de040 + 2061 from unknown:0

I'm using gptzfsboot, and the boot blocks are current.  The previous
loader works fine - boot loader_lua and loader_4th are ok.  But the
current loaders, both ula and 4th, fail with the same panic (the
message reproduced is from loader_4th).

Cyrus Rahman