[m-rev.] for review: Disable tabling progs in parallel grades in tests/debugger.

[Peter Wang]

tests/debugger/Mmakefile:
    As above. In particular, the loopcheck test would run indefinitely
    until killed, generating copious amount of output in the process.

diff --git a/tests/debugger/Mmakefile b/tests/debugger/Mmakefile
index 12d554770..601414925 100644
--- a/tests/debugger/Mmakefile
+++ b/tests/debugger/Mmakefile
@@ -40,7 +40,6 @@ NONRETRY_PROGS = \
 	exception_vars			\
 	existential_type_classes	\
 	exported_eqv_type		\
-	fib				\
 	field_names			\
 	foreign_type			\
 	higher_order			\
@@ -49,7 +48,6 @@ NONRETRY_PROGS = \
 	label_layout			\
 	lambdatest			\
 	list_cmd			\
-	loopcheck			\
 	lval_desc_array			\
 	mdbrc_test			\
 	multi_parameter			\
@@ -75,6 +73,10 @@ NONRETRY_PROGS = \
 	user_event			\
 	user_event_2
 
+TABLING_PROGS = \
+	fib				\
+	loopcheck
+
 # We currently don't pass this test.
 #	deeply_nested_typeinfo
 # This test is currently not useful.
@@ -121,6 +123,12 @@ ifneq "$(findstring decldebug,$(GRADE))" ""
     SHALLOW_PROGS :=
 endif
 
+# Tabling is not compatible with parallel execution,
+# so tests exercising tabling will never succeed in .par grades.
+ifneq "$(findstring par,$(GRADE))" ""
+    TABLING_PROGS :=
+endif
+
 # The sensitive tests are so named because they are sensitive to details
 # of code generation. We therefore execute them only in a minimal set of
 # grades that still ensures good test coverage. For example, the tests
-- 
2.31.0