tests/tcg/arc64: enable {LD,ST}DL tests

For arc64, the Makefile lines adding 128-bit load/store tests to the
list of tests to run were commented out. Since there seems to be no
reason for this, restore these lines to increase test coverage.

Signed-off-by: Artemiy Volkov <artemiy@synopsys.com>

Author: artemiy-volkov

tests/tcg/arc64/Makefile

@@ -92,8 +92,8 @@ TESTCASES += check_vpack4hm.tst
 TESTCASES += check_qmach.tst
 # arc64
 #TESTCASES += check_swapl.tst
-#TESTCASES += check_lddl.tst
-#TESTCASES += check_stdl.tst
+TESTCASES += check_lddl.tst
+TESTCASES += check_stdl.tst
 
 all: $(TESTCASES)
 OBJECTS = ivt.o