Prevent bytecode optimization from remove mk* instructions.

These instructions read from the stack, and therefor have side effects.
Removing them without clearing the stack results in broken bytecode.

src/core/bytecode.c

@@ -226,6 +226,7 @@ void janet_bytecode_movopt(JanetFuncDef *def) {
                 case JOP_LOAD_TRUE:
                 case JOP_LOAD_FALSE:
                 case JOP_LOAD_SELF:
+                    break;
                 case JOP_MAKE_ARRAY:
                 case JOP_MAKE_BUFFER:
                 case JOP_MAKE_STRING:
@@ -233,6 +234,8 @@ void janet_bytecode_movopt(JanetFuncDef *def) {
                 case JOP_MAKE_TABLE:
                 case JOP_MAKE_TUPLE:
                 case JOP_MAKE_BRACKET_TUPLE:
+                    /* Reads from the stack, don't remove */
+                    janetc_regalloc_touch(&ra, DD);
                     break;
 
                 /* Read A */

test/suite-boot.janet

@@ -961,4 +961,11 @@
 # (pp (disasm case-2))
 # (pp (disasm case-3))
 
+# Regression #1330
+(defn regress-1330 [&]
+  (def a [1 2 3])
+  (def b [;a])
+  (identity a))
+(assert (= [1 2 3] (regress-1330)) "regression 1330")
+
 (end-suite)