fix: primitive types are allowed in compound literal expressions

grammar.js

@@ -1111,7 +1111,7 @@ module.exports = grammar(C, {
     compound_literal_expression: ($, original) => choice(
       original,
       seq(
-        field('type', $._class_name),
+        field('type', choice($._class_name, $.primitive_type)),
         field('value', $.initializer_list),
       ),
     ),

test/corpus/expressions.txt

@@ -32,6 +32,7 @@ Compound literals without parentheses
 
 T x = T{0};
 U<V> y = U<V>{0};
+int x = int{1};
 
 --------------------------------------------------------------------------------
 
@@ -58,6 +59,14 @@ U<V> y = U<V>{0};
           (template_argument_list
             (type_descriptor
               (type_identifier))))
+        (initializer_list
+          (number_literal)))))
+  (declaration
+    (primitive_type)
+    (init_declarator
+      (identifier)
+      (compound_literal_expression
+        (primitive_type)
         (initializer_list
           (number_literal))))))