[PATCH] [Bug #21814] Fix negative bignum modulo

	If modulo is zero, do not  apply bias even if the divisor is zero.
	`BIGNUM_POSITIVE_P` is true even on bignum zero.

... instead, just calculate the value unless it is too big.
Also, this change raises an ArgumentError if it is expected to exceed
16 GB in a 64-bit environment.

(It is possible to calculate it straightforward, but it would likely be
out-of-memory, so I didn't think it would make sense.)

[Feature #20811]

```
C:\vcpkg\installed\x64-windows\include\gmp.h(2237): warning C4146: unary minus operator applied to unsigned type, result still unsigned
```

Integer.sqrt uses Newton's method.
This pull request reduces the precision which was unnecessarily high in each calculation step.

This `st_table` is used to both mark and pin classes
defined from the C API. But `vm->mark_object_ary` already
does both much more efficiently.

Currently a Ruby process starts with 252 rooted classes,
which uses `7224B` in an `st_table` or `2016B` in an `RArray`.

So a baseline of 5kB saved, but since `mark_object_ary` is
preallocated with `1024` slots but only use `405` of them,
it's a net `7kB` save.

`vm->mark_object_ary` is also being refactored.

Prior to this changes, `mark_object_ary` was a regular `RArray`, but
since this allows for references to be moved, it was marked a second
time from `rb_vm_mark()` to pin these objects.

This has the detrimental effect of marking these references on every
minors even though it's a mostly append only list.

But using a custom TypedData we can save from having to mark
all the references on minor GC runs.

Addtionally, immediate values are now ignored and not appended
to `vm->mark_object_ary` as it's just wasted space.

[Feature #16495]

assert does not print the bug report, only the file and line number of
the assertion that failed. RUBY_ASSERT prints the full bug report, which
makes it much easier to debug.