Sort procedures by source positions.

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 551dcd3e979bc3693ce8a91e5099292897f77122..60e05d621d6886d26bfd7a327719a3eef74e29fc 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
@@ -51,7 +51,8 @@ import 'kernel_builder.dart'
         PrefixBuilder,
         ProcedureBuilder,
         TypeBuilder,
-        TypeVariableBuilder;
+        TypeVariableBuilder,
+        compareProcedures;
 
 class KernelLibraryBuilder
     extends SourceLibraryBuilder<KernelTypeBuilder, Library> {
@@ -324,6 +325,7 @@ class KernelLibraryBuilder
   Library build() {
     super.build();
     library.name = name;
+    library.procedures.sort(compareProcedures);
     return library;
   }