Eliminate dependencies on assemblers and code stubs in precompiled runtime.

runtime/vm/megamorphic_cache_table.cc

Index: runtime/vm/megamorphic_cache_table.cc
diff --git a/runtime/vm/megamorphic_cache_table.cc b/runtime/vm/megamorphic_cache_table.cc
index 3008fae113cd8f0d6d921b110e9bf8f8bb079043..2c63513c2a5aa6c1c5ea6cbc1ce78065aab1aec1 100644
--- a/runtime/vm/megamorphic_cache_table.cc
+++ b/runtime/vm/megamorphic_cache_table.cc
@@ -50,6 +50,7 @@ RawFunction* MegamorphicCacheTable::miss_handler(Isolate* isolate) {
 }
 
 
+#if !defined(DART_PRECOMPILED_RUNTIME)
 void MegamorphicCacheTable::InitMissHandler(Isolate* isolate) {
   // The miss handler for a class ID not found in the table is invoked as a
   // normal Dart function.
@@ -80,6 +81,7 @@ void MegamorphicCacheTable::InitMissHandler(Isolate* isolate) {
          Function::null());
   isolate->object_store()->SetMegamorphicMissHandler(code, function);
 }
+#endif  // !defined(DART_PRECOMPILED_RUNTIME)
 
 
 void MegamorphicCacheTable::PrintSizes(Isolate* isolate) {