Lambda cleanup

RELNOTES: None.
PiperOrigin-RevId: 160516183
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/Parser.java b/src/main/java/com/google/devtools/build/lib/syntax/Parser.java
index df37954..ae97362 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/Parser.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/Parser.java
@@ -568,12 +568,7 @@
 
   // arg_list ::= ( (arg ',')* arg ','? )?
   private List<Argument.Passed> parseFuncallArguments() {
-    List<Argument.Passed> arguments =
-        parseFunctionArguments(new Supplier<Argument.Passed>() {
-              @Override public Argument.Passed get() {
-                return parseFuncallArgument();
-              }
-            });
+    List<Argument.Passed> arguments = parseFunctionArguments(() -> parseFuncallArgument());
     try {
       Argument.validateFuncallArguments(arguments);
     } catch (Argument.ArgumentException e) {
@@ -1310,7 +1305,8 @@
     expect(TokenKind.DEF);
     Identifier ident = parseIdent();
     expect(TokenKind.LPAREN);
-    List<Parameter<Expression, Expression>> params = parseParameters();
+    List<Parameter<Expression, Expression>> params =
+        parseFunctionArguments(() -> parseFunctionParameter());
     FunctionSignature.WithValues<Expression, Expression> signature = functionSignature(params);
     expect(TokenKind.RPAREN);
     expect(TokenKind.COLON);
@@ -1330,15 +1326,6 @@
     }
   }
 
-  private List<Parameter<Expression, Expression>> parseParameters() {
-    return parseFunctionArguments(
-        new Supplier<Parameter<Expression, Expression>>() {
-          @Override public Parameter<Expression, Expression> get() {
-            return parseFunctionParameter();
-          }
-        });
-  }
-
   /**
    * Parse a list of Argument-s. The arguments can be of class Argument.Passed or Parameter,
    * as returned by the Supplier parseArgument (that, taking no argument, must be closed over