Re-add option handling; fix builtin type assertion

Now need to wait for coder3101/tree-sitter-proto#23 to land to really
sync this with upstream.

runtime/queries/proto/highlights.scm

@@ -31,6 +31,16 @@
 (block_lit
   (identifier) @property)
 
+; Extension option names, e.g. option (foo.bar) = ...
+(option
+  (full_ident
+    (identifier) @variable))
+
+(option
+  (full_ident
+    (identifier)
+    (identifier) @variable.member))
+
 [
   "option"
   "syntax"

tests/query/highlights/proto/test.proto

@@ -19,19 +19,27 @@ import "github.com/gogo/protobuf/gogoproto/gogo.proto";
 //<- @keyword.import
 
 option (gogoproto.sizer_all) = true;
+//      ^^^^^^^^^ @variable
+//                ^^^^^^^^^ @variable.member
 option (gogoproto.marshaler_all) = true;
+//      ^^^^^^^^^ @variable
+//                ^^^^^^^^^^^^^ @variable.member
 option (gogoproto.unmarshaler_all.foo) = true;
+//      ^^^^^^^^^ @variable
+//                ^^^^^^^^^^^^^^^ @variable.member
+//                               ^ @punctuation.delimiter
+//                                ^^^ @variable.member
 
 message LogContent
 //<- @keyword.type
 {
     required string Key = 1;
-//           ^^^^^^ @type
+//           ^^^^^^ @type.builtin
 //                  ^^^ @property
 //                      ^ @operator
 //                        ^ @number
     required string Value = 2;
-//           ^^^^^^ @type
+//           ^^^^^^ @type.builtin
 //                  ^^^^^ @property
     required CustomType Value = 2;
 //  ^^^^^^^^ @keyword.modifier