patch 9.0.1630: "make clean" at the toplevel fails

Problem:    "make clean" at the toplevel fails.
Solution:   Clean the indent and syntax directories in a sub-shell.  (Ben
            Jackson, closes #12536, closes #12526)

Author: puremourning

Makefile

@@ -46,10 +46,8 @@ all install uninstall tools config configure reconfig proto depend lint tags typ
 	fi
 	@# When the target is "clean" also clean for the indent and syntax tests.
 	@if test "$@" = "clean" -o "$@" = "distclean" -o "$@" = "testclean"; then \
-		cd runtime/indent && \
-			$(MAKE) clean; \
-		cd runtime/syntax && \
-			$(MAKE) clean; \
+		(cd runtime/indent && $(MAKE) clean); \
+		(cd runtime/syntax && $(MAKE) clean); \
 	fi
 
 # Executable used for running the indent tests.

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1630,
 /**/
     1629,
 /**/