Canonicalize mixin applications by their name

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

Index: pkg/front_end/lib/src/fasta/kernel/kernel_library_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/kernel_library_builder.dart b/pkg/front_end/lib/src/fasta/kernel/kernel_library_builder.dart
index 82b942e682295b5c79cd1eaefd8d9acdc213fe33..cb5437c6aa6136cb91e0fa44bbf3b94f881d5b47 100644
--- a/pkg/front_end/lib/src/fasta/kernel/kernel_library_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/kernel_library_builder.dart
@@ -61,7 +61,8 @@ class KernelLibraryBuilder
     extends SourceLibraryBuilder<KernelTypeBuilder, Library> {
   final Library library;
 
-  final List<Class> mixinApplicationClasses = <Class>[];
+  final Map<String, SourceClassBuilder> mixinApplicationClasses =
+      <String, SourceClassBuilder>{};
 
   final List<List> argumentsWithMissingDefaultValues = <List>[];
 
@@ -351,7 +352,6 @@ class KernelLibraryBuilder
     super.includePart(part);
     nativeMethods.addAll(part.nativeMethods);
     boundlessTypeVariables.addAll(part.boundlessTypeVariables);

[ahe, 2017/02/23 14:38:15]

assert(mixinApplicationClasses.isEmpty);

-    mixinApplicationClasses.addAll(part.mixinApplicationClasses);
   }
 }