Add ':=' to 'operator'

test/corpus/comments.txt

@@ -112,10 +112,12 @@ end
     (comment)
     (variable_declaration
       (identifier)
+      (operator)
       (integer_literal))
     (comment)
     (variable_declaration
       (identifier)
+      (operator)
       (integer_literal))
     (comment)
     (comment)

test/corpus/control_flow.txt

@@ -65,6 +65,7 @@ for i := 12 to nil do "42"
 (source_file
   (for_expression
     index: (identifier)
+    (operator)
     start: (integer_literal)
     end: (nil_literal)
     body: (string_literal)))
@@ -134,6 +135,7 @@ for i := break to break do while break do break
 (source_file
   (for_expression
     (identifier)
+    (operator)
     (break_expression)
     (break_expression)
     (while_expression

test/corpus/declarations.txt

@@ -217,6 +217,7 @@ var a := 12
 (source_file
   (variable_declaration
     name: (identifier)
+    (operator)
     value: (integer_literal)))
 
 ================================================================================
@@ -231,6 +232,7 @@ var a : int := 27
   (variable_declaration
     name: (identifier)
     type: (type_identifier)
+    (operator)
     value: (integer_literal)))
 
 ================================================================================
@@ -245,9 +247,11 @@ var b := 27
 (source_file
   (variable_declaration
     name: (identifier)
+    (operator)
     value: (integer_literal))
   (variable_declaration
     name: (identifier)
+    (operator)
     value: (integer_literal)))
 
 ================================================================================

test/corpus/expressions.txt

@@ -150,10 +150,12 @@ a := array[12] := record.field
 (source_file
   (assignment_expression
     left: (identifier)
+    (operator)
     right: (assignment_expression
       left: (array_value
         array: (identifier)
         index: (integer_literal))
+      (operator)
       right: (record_value
         record: (identifier)
         field: (field_identifier)))))