Allow back-references in syntax-propertize-rules.

* lisp/emacs-lisp/syntax.el (syntax-propertize--shift-groups-and-backrefs):
Renamed from syntax-propertize--shift-groups, and also shift
back-references.
(syntax-propertize-rules): Adapt docstring and use renamed function.
* test/lisp/emacs-lisp/syntax-tests.el: New test.
(syntax-propertize--shift-groups-and-backrefs): New ERT test.
1 job for master in 56 minutes and 43 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
failed #6028
test-all

00:56:43

 
Name Stage Failure
failed
test-all Test
make[2]: *** [check-doit] Error 1
make[1]: *** [check-expensive] Error 2
make: *** [check-expensive] Error 2
Makefile:319: recipe for target 'check-doit' failed
make[2]: Leaving directory '/builds/emacs/emacs/test'
Makefile:294: recipe for target 'check-expensive' failed
make[1]: Leaving directory '/builds/emacs/emacs/test'
Makefile:959: recipe for target 'check-expensive' failed
ERROR: Job failed: exit code 1