Add + before command to parent make rules (make gmake aware that the

command will execute a submake, and avoid errors about jobserver).

Testsuite/test/makefile

@@ -8,63 +8,63 @@
 all: all0 all1 all2 all3 all4 all5 all6 all7 all8
 
 all0:
-	@for DIR in [0-9_aAbBcC]* ; do \
+	@+for DIR in [0-9_aAbBcC]* ; do \
 	  if test -d "$$DIR"; then \
 	    ( ./run_testsuite "$$DIR" ) \
 	  fi; \
 	done
 
 all1:
-	@for DIR in [dDeEfF]*; do \
+	@+for DIR in [dDeEfF]*; do \
 	  if test -d "$$DIR"; then \
 	    ( ./run_testsuite "$$DIR" ) \
 	  fi; \
 	done
 
 all2:
-	@for DIR in [gGhHiI]*; do \
+	@+for DIR in [gGhHiI]*; do \
 	  if test -d "$$DIR"; then \
 	    ( ./run_testsuite "$$DIR" ) \
 	  fi; \
 	done
 
 all3:
-	@for DIR in [jJkKlL]*; do \
+	@+for DIR in [jJkKlL]*; do \
 	  if test -d "$$DIR"; then \
 	    ( ./run_testsuite "$$DIR" ) \
 	  fi; \
 	done
 
 all4:
-	@for DIR in [mMnNoO]*; do \
+	@+for DIR in [mMnNoO]*; do \
 	  if test -d "$$DIR"; then \
 	    ( ./run_testsuite "$$DIR" ) \
 	  fi; \
 	done
 
 all5:
-	@for DIR in [pPqQrR]*; do \
+	@+for DIR in [pPqQrR]*; do \
 	  if test -d "$$DIR"; then \
 	    ( ./run_testsuite "$$DIR" ) \
 	  fi; \
 	done
 
 all6:
-	@for DIR in [sStTuU]*; do \
+	@+for DIR in [sStTuU]*; do \
 	  if test -d "$$DIR"; then \
 	    ( ./run_testsuite "$$DIR" ) \
 	  fi; \
 	done
 
 all7:
-	@for DIR in [vVwWxX]*; do \
+	@+for DIR in [vVwWxX]*; do \
 	  if test -d "$$DIR"; then \
 	    ( ./run_testsuite "$$DIR" ) \
 	  fi; \
 	done
 
 all8:
-	@for DIR in [yYzZ]*; do \
+	@+for DIR in [yYzZ]*; do \
 	  if test -d "$$DIR"; then \
 	    ( ./run_testsuite "$$DIR" ) \
 	  fi; \