Get `ruby_nonempty_memcpy` to have C linkage

	Fixes [Bug #17788]
	---
	 include/ruby/internal/memory.h | 2 ++
	 1 file changed, 2 insertions(+)

	Fix stack buffer overflow

	https://hackerone.com/reports/1306859
	---
	 include/ruby/internal/memory.h | 6 +++---
	 random.c                       | 7 ++-----
	 2 files changed, 5 insertions(+), 8 deletions(-)

	intern/select/posix.h: remove unused parameter from rb_fd_dup

	This unused parameter seems to be accidently introduced by https://github.com/ruby/ruby/commit/9e6e39c
	---
	 include/ruby/internal/intern/select/posix.h | 3 +--
	 1 file changed, 1 insertion(+), 2 deletions(-)

The count of rb_alloc_tmp_buffer_with_count is the allocation size
counted in VALUE size but not in the requested element size.

Co-authored-by: Yusuke Endoh <mame@ruby-lang.org>
Co-authored-by: Koichi Sasada <ko1@atdot.net>

expose some C-APIs to try to make ractor utilities on external gems.

* add
  * rb_ractor_local_storage_value_lookup() to check availability
* expose
  * rb_ractor_make_shareable()
  * rb_ractor_make_shareable_copy()
  * rb_proc_isolate() (not public)
  * rb_proc_isolate_bang() (not public)
  * rb_proc_ractor_make_shareable() (not public)

Pointed out by @shyouhei.

NOTE: Already we have dropped the support for older MSVCs,
probably prior to 1300 or 1400.  Remove the conditional code,
especially in win32/Makefile.sub.

"experimental_everything" makes the assigned value, it means
the assignment change the state of assigned value.
"experimental_copy" tries to make a deep copy and make copyied object
sharable.

Now we need atomic operations, which are lighter than mutex, more
widely for extension libraries because of Ractor.