Makefile: regenerate perl/build/* if GIT-PERL-DEFINES changes

Change the logic to generate perl/build/* to regenerate those files if
GIT-PERL-DEFINES changes. This ensures that e.g. changing localedir
will result in correctly re-generated files.

I don't think that ever worked. The brokenness pre-dates my
20d2a30 (Makefile: replace perl/Makefile.PL with simple make
rules, 2017-12-10).

Signed-off-by: Ævar Arnfjörð Bjarmason <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: avar

Makefile

@@ -2676,7 +2676,7 @@ endif
 NO_PERL_CPAN_FALLBACKS_SQ = $(subst ','\'',$(NO_PERL_CPAN_FALLBACKS))
 endif
 
-perl/build/lib/%.pm: perl/%.pm
+perl/build/lib/%.pm: perl/%.pm GIT-PERL-DEFINES
 	$(QUIET_GEN)mkdir -p $(dir $@) && \
 	sed -e 's|@@LOCALEDIR@@|$(perl_localedir_SQ)|g' \
 	    -e 's|@@NO_PERL_CPAN_FALLBACKS@@|$(NO_PERL_CPAN_FALLBACKS_SQ)|g' \