ASSERT "ma->start + ma->os_data.alignment == base"

This happens reliably in a proprietary AArch64 app running on ThunderX2 on a 5.3.12-222-64kb kernel:

<CURIOSITY : ma->start + ma->os_data.alignment == base in file dynamorio/core/unix/os.c line 7720
version 7.91.18357, custom build

I have not looked into the details; just filing various issues seen with this app and then will go back through them.