feat(ls64): add a test for 64byte loads/stores instructions

This patch adds a test to verify the 64 byte load and store
instructions introduced by FEAT_LS64.
The test primarily executes instructions:
1. LD64B
2. ST64B
and ensures that the NS-EL2 has no dependency on EL3 while
running them.

Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
Signed-off-by: Juan Pablo Conde <juanpablo.conde@arm.com>
Change-Id: I7a4ca0ee4a2c18bf0de030c72e35eb218bc6364c
diff --git a/include/common/test_helpers.h b/include/common/test_helpers.h
index ced1745..52d41b0 100644
--- a/include/common/test_helpers.h
+++ b/include/common/test_helpers.h
@@ -337,6 +337,15 @@
 		}								\
 	} while (false)
 
+#define SKIP_TEST_IF_LS64_NOT_SUPPORTED()					\
+	do {									\
+		if (get_feat_ls64_support() ==					\
+			ID_AA64ISAR1_LS64_NOT_SUPPORTED) {			\
+			tftf_testcase_printf("ARMv8.7-ls64 not supported");	\
+			return TEST_RESULT_SKIPPED;				\
+		}								\
+	} while (false)
+
 /* Helper macro to verify if system suspend API is supported */
 #define is_psci_sys_susp_supported()	\
 		(tftf_get_psci_feature_info(SMC_PSCI_SYSTEM_SUSPEND)		\