constness fixes, round-trip and fuzz-testing for CHOICE
diff --git a/tests/tests-asn1c-compiler/47-set-ext-OK.asn1.-Pfwide-types b/tests/tests-asn1c-compiler/47-set-ext-OK.asn1.-Pfwide-types
index 6142463..1a55fe8 100644
--- a/tests/tests-asn1c-compiler/47-set-ext-OK.asn1.-Pfwide-types
+++ b/tests/tests-asn1c-compiler/47-set-ext-OK.asn1.-Pfwide-types
@@ -44,7 +44,7 @@
 		.type = &asn_DEF_INTEGER,
 		.type_selector = 0,
 		{ .oer_constraints = 0, .per_constraints = 0, .general_constraints = 0 },
-		.default_value = 0,
+		0, 0, /* No default value */
 		.name = "i"
 		},
 };
@@ -131,7 +131,7 @@
 		.type = &asn_DEF_INTEGER,
 		.type_selector = 0,
 		{ .oer_constraints = 0, .per_constraints = 0, .general_constraints = 0 },
-		.default_value = 0,
+		0, 0, /* No default value */
 		.name = "i"
 		},
 };
@@ -216,7 +216,7 @@
 		.type = &asn_DEF_INTEGER,
 		.type_selector = 0,
 		{ .oer_constraints = 0, .per_constraints = 0, .general_constraints = 0 },
-		.default_value = 0,
+		0, 0, /* No default value */
 		.name = "i"
 		},
 };
@@ -230,7 +230,7 @@
 	sizeof(((struct T3 *)0)->present),
 	.tag2el = asn_MAP_T3_tag2el_1,
 	.tag2el_count = 1,	/* Count of tags in the map */
-	.canonical_order = 0,
+	0, 0,
 	.ext_start = 1	/* Extensions start */
 };
 asn_TYPE_descriptor_t asn_DEF_T3 = {
@@ -291,7 +291,7 @@
 		.type = &asn_DEF_INTEGER,
 		.type_selector = 0,
 		{ .oer_constraints = 0, .per_constraints = 0, .general_constraints = 0 },
-		.default_value = 0,
+		0, 0, /* No default value */
 		.name = "i"
 		},
 };
@@ -305,7 +305,7 @@
 	sizeof(((struct T4 *)0)->present),
 	.tag2el = asn_MAP_T4_tag2el_1,
 	.tag2el_count = 1,	/* Count of tags in the map */
-	.canonical_order = 0,
+	0, 0,
 	.ext_start = 1	/* Extensions start */
 };
 asn_TYPE_descriptor_t asn_DEF_T4 = {