merge revision(s) 0846c2da,6c7cb00c: [Backport #16376]

	Check backref number buffer overrun [Bug #16376]

	---
	 regcomp.c                | 21 ++++++++++++---------
	 test/ruby/test_regexp.rb |  6 ++++++
	 2 files changed, 18 insertions(+), 9 deletions(-)

	test/ruby/test_regexp.rb: Avoid "ambiguity between regexp and two
	 divisions"

	---
	 test/ruby/test_regexp.rb | 2 +-
	 1 file changed, 1 insertion(+), 1 deletion(-)