Fix latin1 character predefinition in the symbol table. The code

runtime/vm/symbols.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/symbols.h"
 
 #include "vm/handles.h"
 #include "vm/handles_impl.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 58 matching lines @@
   for (intptr_t i = 1; i < Symbols::kMaxPredefinedId; i++) {
     // The symbol_table needs to be reloaded as it might have grown in the
     // previous iteration.
     symbol_table = object_store->symbol_table();
     str = OneByteString::New(names[i], Heap::kOld);
     Add(symbol_table, str);
     predefined_[i] = str.raw();
   }
   Object::RegisterSingletonClassNames();
 
-  for (int32_t c = 0; c <= kMaxOneCharCodeSymbol; c++) {
+  // Add Latin1 characters as Symbols, so that Symbols::FromCharCode is fast.
+  for (intptr_t c = 0; c < kMaxOneCharCodeSymbol; c++) {
+    // The symbol_table needs to be reloaded as it might have grown in the
+    // previous iteration.
+    symbol_table = object_store->symbol_table();
     ASSERT(kMaxPredefinedId + c < kMaxId);
-    predefined_[kMaxPredefinedId + c] = FromUTF32(&c, 1);
+    ASSERT(Utf::IsLatin1(c));
+    uint8_t ch = static_cast<uint8_t>(c);
+    str = OneByteString::New(&ch, 1, Heap::kOld);
+    Add(symbol_table, str);
+    predefined_[kMaxPredefinedId + c] = str.raw();
   }
 
   predefined_handles_ = new ReadOnlyHandles();
 #define INITIALIZE_SYMBOL_HANDLE(symbol)                                       \
   symbol##_handle_ = reinterpret_cast<String*>(                                \
       predefined_handles_->AllocateHandle());                                  \
   *symbol##_handle_ = symbol();
 PREDEFINED_SYMBOL_HANDLES_LIST(INITIALIZE_SYMBOL_HANDLE)
 #undef INITIALIZE_SYMBOL_HANDLE
 }
@@ skipping 358 matching lines @@
 }
 
 
 RawObject* Symbols::GetVMSymbol(intptr_t object_id) {
   ASSERT(IsVMSymbolId(object_id));
   intptr_t i = (object_id - kMaxPredefinedObjectIds);
   return (i > 0 && i < Symbols::kMaxId) ? predefined_[i] : Object::null();
 }
 
 }  // namespace dart