merge revision(s) 01bfd1a2,1c120efe,31378dc0: [Backport #20228] (#10301)

Fix memory leak in OnigRegion when match raises

	[Bug #20228]

	rb_reg_onig_match can raise a Regexp::TimeoutError, which would cause
	the OnigRegion to leak.

	Fix memory leak in stk_base when Regexp timeout

	[Bug #20228]

	If rb_reg_check_timeout raises a Regexp::TimeoutError, then the stk_base
	will leak.

	Add memory leak test for Regexp timeout

	[Bug #20228]