ubsan fixes, alignment in u3a_pile - #1072
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Strange CI behavior in #1071 prompted me to run CI tests locally with UBSan, and fix all places where it complained.
The most substantial fix is introduction of alignment in
u3a_pile. I have a faint memory that something like this was supposed to be added to Vere but was never merged, so let's discuss it again. Inu3a_pile_prepwe align the stack and store both stack offsets before and after the alignment. Inu3a_pile_donewe comparecap_pwith the post-alignment value, and if the stack is empty we restore it to the post-alignment value. Alignment is assumed to be a power of two, and the input alignment is in bytes, just like the length.In unix.c ubsan complained that we increment a null pointer, which is supposed to be illegal? I refactored it slightly so that we formally increment it only if it is not null.
In mars.c the function pointer type and the actual function were technically incompatible.
The rest is
1 << Xtype fixes.