src/test: install test utilities as part of installcheck

Instead of making the top-level Makefile run `make install` as part of
its test run, make installation a prerequisite for installcheck, just
like isolation2. This will simplify recursion logic.

GNUmakefile.in

@@ -160,9 +160,9 @@ distclean maintainer-clean:
 # a running server. This is what the CI pipeline runs.
 installcheck-world:
 	$(MAKE) -C src/test installcheck-good
-	$(MAKE) -C src/test/fsync install && $(MAKE) -C src/test/fsync installcheck
-	$(MAKE) -C src/test/walrep install && $(MAKE) -C src/test/walrep installcheck
-	$(MAKE) -C src/test/heap_checksum install && $(MAKE) -C src/test/heap_checksum installcheck
+	$(MAKE) -C src/test/fsync installcheck
+	$(MAKE) -C src/test/walrep installcheck
+	$(MAKE) -C src/test/heap_checksum installcheck
 	$(MAKE) -C src/test/isolation installcheck
 	$(MAKE) -C src/test/isolation2 installcheck
 	$(MAKE) -C src/pl installcheck

src/test/fsync/Makefile

@@ -11,3 +11,7 @@ include $(top_builddir)/src/Makefile.global
 
 NO_PGXS = 1
 include $(top_srcdir)/src/makefiles/pgxs.mk
+
+# Ease the top-level Makefile's job a little bit, and install supporting
+# libraries as part of installcheck.
+installcheck: install

src/test/heap_checksum/Makefile

@@ -11,3 +11,7 @@ include $(top_builddir)/src/Makefile.global
 
 NO_PGXS = 1
 include $(top_srcdir)/src/makefiles/pgxs.mk
+
+# Ease the top-level Makefile's job a little bit, and install supporting
+# libraries as part of installcheck.
+installcheck: install

src/test/walrep/Makefile

@@ -20,3 +20,7 @@ REGRESS_OPTS = --dbname="walrep_regression"
 
 NO_PGXS = 1
 include $(top_srcdir)/src/makefiles/pgxs.mk
+
+# Ease the top-level Makefile's job a little bit, and install supporting
+# libraries as part of installcheck.
+installcheck: install