Clean up duplicate type inference code for fetching parameter types.

pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart

Index: pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart
diff --git a/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart b/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart
index 1efc05f797d9bc72eb9666fa44ef0d924e07853e..34a3e3dc720021be87b60adb1dc94f049c926e6a 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/type_inferrer.dart
@@ -461,18 +461,6 @@ abstract class TypeInferrerImpl extends TypeInferrer {
   /// initializer.
   Expression getFieldInitializer(KernelField field);
 
-  DartType getNamedParameterType(FunctionType functionType, String name) {
-    return functionType.getNamedParameter(name) ?? const DynamicType();
-  }
-
-  DartType getPositionalParameterType(FunctionType functionType, int i) {
-    if (i < functionType.positionalParameters.length) {
-      return functionType.positionalParameters[i];
-    } else {
-      return const DynamicType();
-    }
-  }
-
   DartType getSetterType(Member interfaceMember, DartType receiverType) {
     if (receiverType is InterfaceType) {
       if (interfaceMember == null) return const DynamicType();