Fix error in sizeof expressions

grammar.coffee

@@ -391,8 +391,9 @@ module.exports =
       cast_expression: ->
         prec(PREC.cast, seq("(", @type_name, ")", @expression))
 
-      sizeof_expression: ->
+      sizeof_expression: -> choice(
         prefix(PREC.sizeof, @expression, keyword("sizeof"))
+        prefix(PREC.sizeof, seq("(", @type_name, ")"), keyword("sizeof")))
 
       subscript_expression: ->
         prec(PREC.subscript, seq(@expression, "[", @expression, "]"))

grammar_test/expressions.txt

@@ -195,6 +195,26 @@ int main() {
         (type_name (type_qualifier) (identifier) (pointer))
         (identifier))))))
 
+============================================
+Sizeof expressions
+============================================
+
+int main() {
+  sizeof x.a;
+  sizeof(x.a);
+  sizeof(const char *);
+}
+
+---
+
+(function_definition
+  (identifier)
+  (direct_declarator (identifier))
+  (compound_statement
+    (expression_statement (sizeof_expression (field_expression (identifier) (identifier))))
+    (expression_statement (sizeof_expression (expression (field_expression (identifier) (identifier)))))
+    (expression_statement (sizeof_expression (type_name (type_qualifier) (identifier) (pointer))))))
+
 ============================================
 Compound literals
 ============================================