Disallow pending interrupts to be checked during `FiberScheduler#unblock`.

Ractors can send signals at any time, so the previous debug assertion can fail if a Ractor sends a signal.

Co-authored-by: Luke Gruber <luke.gruber@shopify.com>

	Suppress gcc 15 unterminated-string-initialization warnings

	Drop an ignored attribute
	MIME-Version: 1.0
	Content-Type: text/plain; charset=UTF-8
	Content-Transfer-Encoding: 8bit

	GCC 13.3.0 (Ubuntu 24.04) emits the following warning:

	../symbol.c: In function ‘rb_id_attrset’:
	../symbol.c:175:9: warning: ‘nonstring’ attribute ignored on objects of type ‘const char[][8]’ [-Wattributes]
	  175 |         RBIMPL_ATTR_NONSTRING() static const char id_types[][8] = {
	      |         ^~~~~~~~~~~~~~~~~~~~~

	Separate `__has_attribute` from `defined(__has_attribute)`

	Fix Visual C warnings:
	```
	regenc.h(121): warning C4067: unexpected tokens following preprocessor directive - expected a newline
	```

	Cast up `int` instruction code to `VALUE`

	Fix Visual C warnings:
	```
	iseq.c(3793): warning C4312: 'type cast': conversion from 'int' to 'void *' of greater size
	iseq.c(3794): warning C4312: 'type cast': conversion from 'int' to 'void *' of greater size
	```

	Do not let files depend on a phony target

	Detect `clock_gettime` and `clock_getres` for winpthreads

	Fix Symbol#to_proc (rb_sym_to_proc) to be ractor safe

	In non-main ractors, don't use `sym_proc_cache`. It is not thread-safe
	to add to this array without a lock and also it leaks procs from one
	ractor to another. Instead, we create a new proc each time. If this
	results in poor performance we can come up with a solution later.

	Fixes [Bug #21354]

	digest.so needs ruby/digest.h which is installed by build-ext

	Copy to path with the base name

[Bug #21170]

st_table reserves -1 as a special hash value to indicate that an entry
has been deleted. So that that's a valid value to be returned from the
hash function, do_hash replaces -1 with 0 so that it is not mistaken for
the sentinel.

Previously, when upgrading an AR table to an ST table,
rb_st_add_direct_with_hash was used which did not perform the same
conversion, this could lead to a hash in a broken state where one if its
entries which was supposed to exist being marked as a tombstone.

The hash could then become further corrupted when the ST table required
resizing as the falsely tombstoned entry would be skipped but it would
be counted in num entries, leading to an uninitialized entry at index
15.

In most cases this will be really rare, unless using a very poorly
implemented custom hash function.

This also adds two debug assertions, one that st_add_direct_with_hash
does not receive the reserved hash value, and a second in
rebuild_table_with, which ensures that after we rebuild/compact a table
it contains the expected number of elements.

Co-authored-by: Alan Wu <alanwu@ruby-lang.org>

	[Bug #20853] Fix Proc#hash to not change after compaction

	The hash value of a Proc must remain constant after a compaction, otherwise
	it may not work as the key in a hash table.

So that it can run without `--disable=gems` option.