Remove deprecated dart:utf library.

runtime/vm/object_store.h

Index: runtime/vm/object_store.h
diff --git a/runtime/vm/object_store.h b/runtime/vm/object_store.h
index 37add484c0b05630629c617e01d0bc95ac5dac80..2bc8cc5aa40a0c953e92c2f316a25b42b85af3d6 100644
--- a/runtime/vm/object_store.h
+++ b/runtime/vm/object_store.h
@@ -30,7 +30,6 @@ class ObjectStore {
     kMath,
     kMirrors,
     kTypedData,
-    kUtf,
   };
 
   ~ObjectStore();
@@ -279,7 +278,6 @@ class ObjectStore {
   RawLibrary* math_library() const { return math_library_; }
   RawLibrary* mirrors_library() const { return mirrors_library_; }
   RawLibrary* typed_data_library() const { return typed_data_library_; }
-  RawLibrary* utf_library() const { return utf_library_; }
   void set_bootstrap_library(BootstrapLibraryId index, const Library& value) {
     switch (index) {
       case kAsync:
@@ -309,9 +307,6 @@ class ObjectStore {
       case kTypedData:
         typed_data_library_ = value.raw();
         break;
-      case kUtf:
-        utf_library_ = value.raw();
-        break;
       default:
         UNREACHABLE();
     }
@@ -480,7 +475,6 @@ class ObjectStore {
   RawLibrary* native_wrappers_library_;
   RawLibrary* root_library_;
   RawLibrary* typed_data_library_;
-  RawLibrary* utf_library_;
   RawGrowableObjectArray* libraries_;
   RawGrowableObjectArray* pending_classes_;
   RawGrowableObjectArray* pending_functions_;