First corelib cleanup patch after unification.

lib/compiler/implementation/compiler.dart

Index: lib/compiler/implementation/compiler.dart
diff --git a/lib/compiler/implementation/compiler.dart b/lib/compiler/implementation/compiler.dart
index f22184e30d276639fb1c1936d6f9042114e7f6fe..ae78cb4558df3a51b275b0ca95a86b416ba9c255 100644
--- a/lib/compiler/implementation/compiler.dart
+++ b/lib/compiler/implementation/compiler.dart
@@ -826,6 +826,14 @@ class Compiler implements DiagnosticListener {
     }
     Token position = element.position();
     Uri uri = element.getCompilationUnit().script.uri;
+
+    // TODO(ager,johnniwinther): The patch support should be
+    // reworked to allow us to get rid of this.
+    if (element.isPatched) {
+      position = element.patch.position();
+      uri = element.patch.getCompilationUnit().script.uri;
+    }
+
     return (position === null)
         ? new SourceSpan(uri, 0, 0)
         : spanFromTokens(position, position, uri);