build: use yacc pattern rule with "y" as stem.

Thanks to a recent discussion in the GNU Make mailing list
about some issue related to grouped patterns, I hit upon the
realization that the rule y.tab.h y.tab.c: parser.y has
a common stem, y, which can be exploited to write a pattern
rule. This is only active in maintainer mode; in user mode,
the y.tab.h and y.tab.c are separately produced from .shipped
files.

* Makefile (y.tab.h): Eliminate rule which detects a removed
y.tab.h.
(y.tab.c): Delete rule, replacing with new rule.
(%.tab.c %.tab.h): New pattern rule, which groups the targets
together.

0 files changed, 0 insertions, 0 deletions