Prefix type and let to replace immutable

core/raw.odin

@@ -1,27 +1,27 @@
-const Any = struct #ordered {
+type Any struct #ordered {
 	data:      rawptr,
 	type_info: ^TypeInfo,
-}
+};
 
-const String = struct #ordered {
+type String struct #ordered {
 	data: ^u8,
 	len:  int,
 };
 
-const Slice = struct #ordered {
+type Slice struct #ordered {
 	data: rawptr,
 	len:  int,
 	cap:  int,
 };
 
-const DynamicArray = struct #ordered {
+type DynamicArray struct #ordered {
 	data:      rawptr,
 	len:       int,
 	cap:       int,
 	allocator: Allocator,
 };
 
-const DynamicMap = struct #ordered {
+type DynamicMap struct #ordered {
 	hashes:  [dynamic]int,
 	entries: DynamicArray,
 };