[kernel] Don't emit field initializers in a redirecting constructor

runtime/vm/kernel_binary_flowgraph.cc

Index: runtime/vm/kernel_binary_flowgraph.cc
diff --git a/runtime/vm/kernel_binary_flowgraph.cc b/runtime/vm/kernel_binary_flowgraph.cc
index 33c85883c08dca768e4f896411db799a63c561f3..e34276668e7b06d77f544a49bef6386b58b371a7 100644
--- a/runtime/vm/kernel_binary_flowgraph.cc
+++ b/runtime/vm/kernel_binary_flowgraph.cc
@@ -2924,11 +2924,31 @@ Fragment StreamingFlowGraphBuilder::BuildInitializers(
     intptr_t constructor_class_parent_offset) {
   Fragment instructions;
 
+  // Start by getting the position of the constructors initializer.
+  intptr_t initializers_offset = -1;
+  {
+    AlternativeReadingScope alt(reader_);
+    SkipFunctionNode();  // read constructors function node.
+    initializers_offset = ReaderOffset();
+  }
+
   // These come from:
   //   class A {
   //     var x = (expr);
   //   }
+  // We don't want to do that when this is a Redirecting Constructors though
+  // (i.e. has a single initializer being of type kRedirectingInitializer).
+  bool is_redirecting_constructor = false;
   {
+    AlternativeReadingScope alt(reader_, initializers_offset);
+    intptr_t list_length = ReadListLength();  // read initializers list length.
+    if (list_length == 1) {
+      Tag tag = ReadTag();
+      if (tag == kRedirectingInitializer) is_redirecting_constructor = true;
+    }
+  }
+
+  if (!is_redirecting_constructor) {
     AlternativeReadingScope alt(reader_, constructor_class_parent_offset);
     ReadClassUntilFields();                   // read first part of class.
     intptr_t list_length = ReadListLength();  // read fields list length.
@@ -2963,9 +2983,7 @@ Fragment StreamingFlowGraphBuilder::BuildInitializers(
   //     A(this.x) : super(expr), y = (expr);
   //   }
   {
-    AlternativeReadingScope alt(reader_);
-    SkipFunctionNode();  // read constructors function node.
-
+    AlternativeReadingScope alt(reader_, initializers_offset);
     intptr_t list_length = ReadListLength();  // read initializers list length.
     for (intptr_t i = 0; i < list_length; ++i) {
       Tag tag = ReadTag();