Fix access to returnTypeOf

pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart

Index: pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
diff --git a/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart b/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
index eedd1d0e3f8b8cb510f4e1e4e0dc01eb1677774b..e2b9a39ddeb493e9ad68686dd5dcf28d06951638 100644
--- a/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
+++ b/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
@@ -176,9 +176,9 @@ class KernelAstAdapter extends KernelElementAdapterMixin {
     return !closedWorld.getCannotThrow(function);
   }
 
-  TypeMask returnTypeOf(ir.Member node) {
+  TypeMask returnTypeOf(ir.Procedure node) {
     return TypeMaskFactory.inferredReturnTypeForElement(
-        getElement(node), _globalInferenceResults);
+        getMethod(node), _globalInferenceResults);
   }
 
   SideEffects getSideEffects(ir.Node node, ClosedWorld closedWorld) {