Add some support for the code-point code-unit distinction.

runtime/vm/symbols.cc

Index: runtime/vm/symbols.cc
diff --git a/runtime/vm/symbols.cc b/runtime/vm/symbols.cc
index 35729643a3d3fc2059087ae0e2a12f251845062a..afd2808a68660bfde22974ec130cf02ec0a397e2 100644
--- a/runtime/vm/symbols.cc
+++ b/runtime/vm/symbols.cc
@@ -98,7 +98,7 @@ RawString* Symbols::New(const char* str) {
   Utf8::Type type;
   intptr_t str_len = strlen(str);
   const uint8_t* utf8_array = reinterpret_cast<const uint8_t*>(str);
-  intptr_t len = Utf8::CodePointCount(utf8_array, str_len, &type);
+  intptr_t len = Utf8::CodeUnitCount(utf8_array, str_len, &type);
   Zone* zone = Isolate::Current()->current_zone();
   if (len == 0) {
     return Symbols::New(reinterpret_cast<uint8_t*>(NULL), 0);