Begin supporting string16 across the core library

core/encoding/cbor/tags.odin

@@ -298,7 +298,7 @@ tag_base64_unmarshal :: proc(_: ^Tag_Implementation, d: Decoder, _: Tag_Number,
 
 	#partial switch t in ti.variant {
 	case reflect.Type_Info_String:
-
+		assert(!t.is_utf16)
 		if t.is_cstring {
 			length  := base64.decoded_len(bytes)
 			builder := strings.builder_make(0, length+1)

core/encoding/cbor/unmarshal.odin

@@ -335,6 +335,8 @@ _unmarshal_value :: proc(d: Decoder, v: any, hdr: Header, allocator := context.a
 _unmarshal_bytes :: proc(d: Decoder, v: any, ti: ^reflect.Type_Info, hdr: Header, add: Add, allocator := context.allocator, loc := #caller_location) -> (err: Unmarshal_Error) {
 	#partial switch t in ti.variant {
 	case reflect.Type_Info_String:
+		assert(!t.is_utf16)
+
 		bytes := err_conv(_decode_bytes(d, add, allocator=allocator, loc=loc)) or_return
 
 		if t.is_cstring {