[Misc #18891]

After 5e86b005c0f2ef30df2f9906c7e2f3abefe286a2, I now think ANYARGS is
dangerous and should be extinct.  This commit deletes ANYARGS from
st_foreach.  I strongly believe that this commit should have had come
with b0af0592fdd9e9d4e4b863fde006d67ccefeac21, which added extra
parameter to st_foreach callbacks.

	[Feature #12142]
	See header of st.c for improvment details.

	You can see all of code history here:
	<https://github.com/vnmakarov/ruby/tree/hash_tables_with_open_addressing>

	This improvement is discussed at
	<https://bugs.ruby-lang.org/issues/12142>
	with many people, especially with Yura Sokolov.

	* st.c: improve st_table.

	* include/ruby/st.h: ditto.

	* internal.h, numeric.c, hash.c (rb_dbl_long_hash): extract a function.

	* ext/-test-/st/foreach/foreach.c: catch up this change.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56650 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

* ext/-test-/st/foreach/foreach.c: get rid of hard coded "%lu",
  since st_data_t depends on the platforms.  use PRIuVALUE with
  casting VALUE instead since there is no specifier for it.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48249 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

The st_foreach and st_foreach_check functions support transitioning
from a packed to an unpacked state during iteration.  However, this
functionality did not get exercised by the current test suite until
now.  This should help us prevent breakage when making modifications
to st.

* ext/-test-/st/foreach/extconf.rb: new file
* ext/-test-/st/foreach/foreach.c: ditto
* test/-ext-/st/test_foreach.rb: ditto
  [Feature #10321]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47856 b2dd03c8-39d4-4d8f-98ff-823fe69b080e