Remove MODULES_big from test_pg_dump

The Makefile for test_pg_dump shouldn't have a MODULES_big line
because there's no actual compiled bit for that extension.  Hopefully
this will fix the Windows buildfarm members which were complaining.

In passing, also add the 'prove_installcheck' bit to the pg_dump and
test_pg_dump Makefiles, to get the buildfarm members to actually run
those tests.

src/bin/pg_dump/Makefile

@@ -45,6 +45,9 @@ installdirs:
 check:
 	$(prove_check)
 
+installcheck:
+	$(prove_installcheck)
+
 uninstall:
 	rm -f $(addprefix '$(DESTDIR)$(bindir)'/, pg_dump$(X) pg_restore$(X) pg_dumpall$(X))
 

src/test/modules/test_pg_dump/Makefile

 # src/test/modules/test_rls_hooks/Makefile
 
-MODULE_big = test_pg_dump
 PGFILEDESC = "test_pg_dump - Test pg_dump with an extension"
 
 EXTENSION = test_pg_dump
@@ -13,6 +12,9 @@ check: prove-check
 prove-check:
 	$(prove_check)
 
+installcheck:
+	$(prove_installcheck)
+
 ifdef USE_PGXS
 PG_CONFIG = pg_config
 PGXS := $(shell $(PG_CONFIG) --pgxs)