[metadata] Make type dup used by inflate_generic_type be cmod aware. F…

…ixes mono#10834

We didn't include cmods when inflating var/mvar cuz we'd mono_metadata_type_dup' the inflated type
and not the (m)var MonoType.

The solution is to add a variant of mono_metadata_type_dup that takes the source of cmods to use.

mono/metadata/class.c

@@ -644,7 +644,7 @@ inflate_generic_type (MonoImage *image, MonoType *type, MonoGenericContext *cont
 		 * while the VAR/MVAR duplicates a type from the context.  So, we need to ensure that the
 		 * ->byref and ->attrs from @type are propagated to the returned type.
 		 */
-		nt = mono_metadata_type_dup (image, inst->type_argv [num]);
+		nt = mono_metadata_type_dup_with_cmods (image, inst->type_argv [num], type);
 		nt->byref = type->byref;
 		nt->attrs = type->attrs;
 		return nt;
@@ -667,7 +667,7 @@ inflate_generic_type (MonoImage *image, MonoType *type, MonoGenericContext *cont
 				num, pname ? pname : "", inst->type_argv [num]->type);
 			return NULL;			
 		}
-		nt = mono_metadata_type_dup (image, inst->type_argv [num]);
+		nt = mono_metadata_type_dup_with_cmods (image, inst->type_argv [num], type);
 		nt->byref = type->byref;
 		nt->attrs = type->attrs;
 		return nt;
@@ -790,7 +790,7 @@ mono_class_inflate_generic_type_with_mempool (MonoImage *image, MonoType *type,
 	if (!inflated) {
 		MonoType *shared = mono_metadata_get_shared_type (type);
 
-		if (shared) {
+		if (shared && !type->has_cmods) {
 			return shared;
 		} else {
 			return mono_metadata_type_dup (image, type);

mono/metadata/metadata-internals.h

@@ -893,6 +893,8 @@ void mono_unload_interface_ids (MonoBitSet *bitset);
 
 
 MonoType *mono_metadata_type_dup (MonoImage *image, const MonoType *original);
+MonoType *mono_metadata_type_dup_with_cmods (MonoImage *image, const MonoType *original, const MonoType *cmods_source);
+
 MonoMethodSignature  *mono_metadata_signature_dup_full (MonoImage *image,MonoMethodSignature *sig);
 MonoMethodSignature  *mono_metadata_signature_dup_mempool (MonoMemPool *mp, MonoMethodSignature *sig);
 MonoMethodSignature  *mono_metadata_signature_dup_add_this (MonoImage *image, MonoMethodSignature *sig, MonoClass *klass);

mono/metadata/metadata.c

@@ -5694,13 +5694,28 @@ mono_metadata_signature_equal (MonoMethodSignature *sig1, MonoMethodSignature *s
  */
 MonoType *
 mono_metadata_type_dup (MonoImage *image, const MonoType *o)
+{
+	return mono_metadata_type_dup_with_cmods (image, o, o);
+}
+
+/**
+ * Works the same way as mono_metadata_type_dup but pick cmods from @cmods_source
+ */
+MonoType *
+mono_metadata_type_dup_with_cmods (MonoImage *image, const MonoType *o, const MonoType *cmods_source)
 {
 	MonoType *r = NULL;
-	size_t sizeof_o = mono_sizeof_type (o);
+	size_t sizeof_o = mono_sizeof_type (cmods_source);
 
 	r = image ? (MonoType *)mono_image_alloc0 (image, sizeof_o) : (MonoType *)g_malloc (sizeof_o);
 
-	memcpy (r, o, sizeof_o);
+	if (cmods_source->has_cmods) {
+		g_assert (!image || image == mono_type_get_cmods (cmods_source)->image);
+		memcpy (r, cmods_source, sizeof_o);
+	}
+
+	memcpy (r, o, sizeof (MonoType));
+	r->has_cmods = cmods_source->has_cmods;
 
 	if (o->type == MONO_TYPE_PTR) {
 		r->data.type = mono_metadata_type_dup (image, o->data.type);