Use a constant for time64 object files.

For a moment there was more than one.  Nicer to have it in a variable anyway.

Also t/mktime64.t wasn't getting run.

Makefile

@@ -7,52 +7,53 @@ WARNINGS = -Wall -ansi -pedantic -Wno-long-long -Wextra -Wdeclaration-after-stat
 CFLAGS   = $(WARNINGS) $(OPTIMIZE) $(INCLUDE)
 COMPILE  = $(CC) $(CFLAGS)
 LINK     = $(COMPILE)
+TIME64_OBJECTS = time64.o
 
-all : time64.o bin/check_max
+all : $(TIME64_OBJECTS) bin/check_max
 
-bin/check_max : time64.o time64_config.h bin/check_max.c
-	$(LINK) time64.o bin/check_max.c -o $@
+bin/check_max : $(TIME64_OBJECTS) time64_config.h bin/check_max.c
+	$(LINK) $(TIME64_OBJECTS) bin/check_max.c -o $@
 
 time64.o : time64_config.h time64.h time64.c Makefile
 
-t/bench : t/bench.c time64.o
-	$(LINK) time64.o t/bench.c -o $@
+t/bench : t/bench.c $(TIME64_OBJECTS)
+	$(LINK) $(TIME64_OBJECTS) t/bench.c -o $@
 
 bench : t/bench
 	time t/bench
 
-t/localtime_test : t/localtime_test.c time64.o
-	$(LINK) time64.o t/localtime_test.c -o $@
+t/localtime_test : t/localtime_test.c $(TIME64_OBJECTS)
+	$(LINK) $(TIME64_OBJECTS) t/localtime_test.c -o $@
 
-t/gmtime_test : t/gmtime_test.c time64.o
-	$(LINK) time64.o t/gmtime_test.c -o $@
+t/gmtime_test : t/gmtime_test.c $(TIME64_OBJECTS)
+	$(LINK) $(TIME64_OBJECTS) t/gmtime_test.c -o $@
 
-t/year_limit.t : t/tap.c t/year_limit.t.c time64.o
-	$(LINK) time64.o t/year_limit.t.c -o $@
+t/year_limit.t : t/tap.c t/year_limit.t.c $(TIME64_OBJECTS)
+	$(LINK) $(TIME64_OBJECTS) t/year_limit.t.c -o $@
 
-t/negative.t : t/tap.c t/negative.t.c time64.o
-	$(LINK) time64.o t/negative.t.c -o $@
+t/negative.t : t/tap.c t/negative.t.c $(TIME64_OBJECTS)
+	$(LINK) $(TIME64_OBJECTS) t/negative.t.c -o $@
 
-t/overflow.t : t/tap.c t/overflow.t.c time64.o
-	$(LINK) time64.o t/overflow.t.c -o $@
+t/overflow.t : t/tap.c t/overflow.t.c $(TIME64_OBJECTS)
+	$(LINK) $(TIME64_OBJECTS) t/overflow.t.c -o $@
 
-t/timegm.t : t/tap.c t/timegm.t.c time64.o
-	$(LINK) time64.o t/timegm.t.c -o $@
+t/timegm.t : t/tap.c t/timegm.t.c $(TIME64_OBJECTS)
+	$(LINK) $(TIME64_OBJECTS) t/timegm.t.c -o $@
 
 t/safe_year.t : t/tap.c t/safe_year.t.c time64.c
 	$(LINK) t/safe_year.t.c -o $@
 
-t/gmtime64.t : t/tap.c t/gmtime64.t.c time64.o
-	$(LINK) time64.o t/gmtime64.t.c -o $@
+t/gmtime64.t : t/tap.c t/gmtime64.t.c $(TIME64_OBJECTS)
+	$(LINK) $(TIME64_OBJECTS) t/gmtime64.t.c -o $@
 
-t/mktime64.t : t/tap.c t/mktime64.t.c time64.o
-	$(LINK) time64.o t/mktime64.t.c -o $@
+t/mktime64.t : t/tap.c t/mktime64.t.c $(TIME64_OBJECTS)
+	$(LINK) $(TIME64_OBJECTS) t/mktime64.t.c -o $@
 
-t/asctime64.t : t/tap.c t/asctime64.t.c time64.o
-	$(LINK) time64.o t/asctime64.t.c -o $@
+t/asctime64.t : t/tap.c t/asctime64.t.c $(TIME64_OBJECTS)
+	$(LINK) $(TIME64_OBJECTS) t/asctime64.t.c -o $@
 
-t/ctime64.t : t/tap.c t/ctime64.t.c time64.o
-	$(LINK) time64.o t/ctime64.t.c -o $@
+t/ctime64.t : t/tap.c t/ctime64.t.c $(TIME64_OBJECTS)
+	$(LINK) $(TIME64_OBJECTS) t/ctime64.t.c -o $@
 
 t/seconds_between_years.t : t/tap.c t/seconds_between_years.t.c time64.c
 	$(LINK) t/seconds_between_years.t.c -o $@
@@ -70,7 +71,7 @@ localtime_tests: t/localtime_test t/gmtime_test
 	TZ=Australia/West t/localtime_test | bzip2 -9 > t/oz_test.out.bz2
 	bzdiff -u t/oz_test.out.bz2 t/oztime.out.bz2 | less -F
 
-tap_tests: t/year_limit.t t/negative.t t/overflow.t t/timegm.t t/safe_year.t t/gmtime64.t t/asctime64.t t/ctime64.t
+tap_tests: t/year_limit.t t/negative.t t/overflow.t t/timegm.t t/mktime64.t t/safe_year.t t/gmtime64.t t/asctime64.t t/ctime64.t
 	@which prove > /dev/null || (echo 'You need prove (from the Test::Harness perl module) to run these tests'; exit 1)
 	@prove --exec '' t/*.t