Fix PARSE position capture combined with SET or COPY
Fix PARSE position capture combined with SET or COPY

The recent extension to allow set-word! usage in SET and COPY rules
introduced a regression: set-word!s (for position capture) in the rule
immediately following a `SET word` or `COPY word` rule cause a match
failure. For example:

    >> parse [x] [set val pos: word!]
    == false  ;; Expected: true

This commit fixes this issue (CureCode issue 2130), a regression caused
by 8db79a9.

Corresponding tests have been added to the test suite
(rebolsource/rebol-test@fe8df53).

Conflicts:
	src/core/u-parse.c

draegtun/ren-c,draegtun/ren-c,giuliolunati/ren-c,hostilefork/rebol,codebybrett/ren-c,rgchris/ren-c,hostilefork/rebol,codebybrett/ren-c,codebybrett/ren-c,kealist/ren-c,rgchris/ren-c,mbk/ren-c,giuliolunati/ren-c,giuliolunati/ren-c,hostilefork/rebol,mbk/ren-c,codebybrett/ren-c,kealist/ren-c,giuliolunati/ren-c,codebybrett/ren-c,rgchris/ren-c,hostilefork/rebol,draegtun/ren-c,giuliolunati/ren-c,rgchris/ren-c,hostilefork/rebol,draegtun/ren-c,codebybrett/ren-c,hostilefork/rebol,kealist/ren-c,rgchris/ren-c,draegtun/ren-c,kealist/ren-c,draegtun/ren-c,kealist/ren-c,kealist/ren-c,mbk/ren-c,mbk/ren-c