Clean up duplicate type inference code for fetching parameter types.

pkg/front_end/lib/src/fasta/kernel/kernel_shadow_ast.dart

Index: pkg/front_end/lib/src/fasta/kernel/kernel_shadow_ast.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/kernel_shadow_ast.dart b/pkg/front_end/lib/src/fasta/kernel/kernel_shadow_ast.dart
index 6e35f2bb3faab50a1be03b25d1b652ed71ef01cb..a351071cf50535419eaab13c436dc63c2de47c7e 100644
--- a/pkg/front_end/lib/src/fasta/kernel/kernel_shadow_ast.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/kernel_shadow_ast.dart
@@ -25,6 +25,7 @@ import 'package:front_end/src/fasta/type_inference/type_inferrer.dart';
 import 'package:front_end/src/fasta/type_inference/type_promotion.dart';
 import 'package:front_end/src/fasta/type_inference/type_schema.dart';
 import 'package:front_end/src/fasta/type_inference/type_schema_elimination.dart';
+import 'package:front_end/src/fasta/type_inference/type_schema_environment.dart';
 import 'package:kernel/ast.dart'
     hide InvalidExpression, InvalidInitializer, InvalidStatement;
 import 'package:kernel/frontend/accessors.dart';
@@ -816,10 +817,10 @@ class KernelFunctionExpression extends FunctionExpression
       for (int i = 0; i < formals.length; i++) {
         if (i < function.positionalParameters.length) {
           formalTypesFromContext[i] =
-              inferrer.getPositionalParameterType(typeContext, i);
+              getPositionalParameterType(typeContext, i);
         } else {
           formalTypesFromContext[i] =
-              inferrer.getNamedParameterType(typeContext, formals[i].name);
+              getNamedParameterType(typeContext, formals[i].name);
         }
       }
       returnContext = typeContext.returnType;