Use register x28 instead of sp for instructions of the form "str x14,…

… [sp]" because sp needs to be 16 byte aligned, but x28 doesn't. There are already were adjustments made to sp, so it will end up as 16 bytes aligned. That includes setting x28 to sp initially, and finally setting sp back to x28.

Combine the two instructions "sub  sp,sp, YottaDB#8" and "str  x14, [sp]" into one (including the change noted above "str  x14, [x28, #-8]!"

sr_aarch64/ci_restart.s

@@ -41,6 +41,8 @@ ENTRY ci_restart
 	mov	x29, sp					/* save sp here - to be restored after op_extexfun or op_extcall */
 	ldr	w9, [x13, #argcnt]			/* argcnt */
 	ADJ_STACK_ALIGN_EVEN_ARGS w9
+	mov	x28, sp					/* xxxxxxx Use x28 instead of sp for store since sp needs 16-byte alignment
+							 * At the end, sp will be properly aligned */
 	mov	w14, w9
 	cmp	w9, wzr					/* if (argcnt > 0) { */
 	b.le	L0
@@ -50,13 +52,16 @@ ENTRY ci_restart
 	add	x12, x12, x10				/* point at last arg */
 L1:
 	ldr	w10, [x12], #-8				/* push arguments backwards to stack */
-	sub	sp, sp, #8
-	str	x10, [sp]
+	str	w10, [x28, #-8]!
+/* xxxxxxx	sub	sp, sp, #8
+	str	x10, [sp] */
 	subs	w9, w9, #1
 	b.ne	L1					/* } */
 L0:
-	sub	sp, sp, #8				/* push arg count on stack */
-	str	x14, [sp]
+	str	x14, [x28, #-8]!				/* push arg count on stack */
+/* xxxxxxx	sub	sp, sp, #8 */				/* push arg count on stack */
+	/* xxxxxxx	str	x14, [sp] */
+	mov	sp, x28						/* Restore actual sp */
 	ldr	x12, [x13, #mask]
 	ldr	w11, [x13, #retaddr]
 	ldr	w10, [x13, #labaddr]