Add type inference for super method invocations.

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

Index: pkg/front_end/lib/src/fasta/kernel/body_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index 4f078bcea0c574873c54fcace2fe13546c9c3e28..1f54e63af0a48d6111cb5650493a2b4a51443f30 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -897,13 +897,15 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
       if (!target.isAccessor) {
         if (areArgumentsCompatible(target.function, node.arguments)) {
           Expression result = new KernelDirectMethodInvocation(
-              new ThisExpression()..fileOffset = node.fileOffset,
+              new KernelThisExpression()..fileOffset = node.fileOffset,
               target,
-              node.arguments);
+              node.arguments)
+            ..fileOffset = node.fileOffset;
           // TODO(ahe): Use [DirectMethodInvocation] when possible, that is,
           // remove the next line:
           result =
-              new KernelSuperMethodInvocation(node.name, node.arguments, null);
+              new KernelSuperMethodInvocation(node.name, node.arguments, target)

[Paul Berry, 2017/06/26 18:57:55]

Peter, can you confirm that passing `target` is the correct thing to do here?

[Siggi Cherem (dart-lang), 2017/06/26 19:47:53]

DBC - the answer might change in the near future when we address
https://github.com/dart-lang/sdk/issues/30000. I expect we will generate
super-calls with a null target on purpose in those cases.

[Paul Berry, 2017/06/27 20:50:17]

Thanks for the heads up.  I'm adding a test case to make sure type inference
won't break in those cases (https://codereview.chromium.org/2958113002/).

+                ..fileOffset = node.fileOffset;
           return result;
         } else {
           isNoSuchMethod = true;
@@ -915,7 +917,7 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
           node.name.name, node.arguments, node.fileOffset);
     }
     Expression receiver = new KernelDirectPropertyGet(
-        new ThisExpression()..fileOffset = node.fileOffset, target);
+        new KernelThisExpression()..fileOffset = node.fileOffset, target);
     // TODO(ahe): Use [DirectPropertyGet] when possible, that is, remove the
     // next line:
     receiver = new KernelSuperPropertyGet(node.name, target);
@@ -992,7 +994,7 @@ class BodyBuilder extends ScopeListener<JumpTarget> implements BuilderHelper {
         noSuchMethodName,
         new Arguments(<Expression>[
           library.loader.instantiateInvocation(
-              new ThisExpression()..fileOffset = charOffset,
+              new KernelThisExpression()..fileOffset = charOffset,
               name,
               arguments,
               charOffset,