Port r10023 to x64 (Add pointer cache field to external string).

src/ia32/codegen-ia32.cc

Index: src/ia32/codegen-ia32.cc
diff --git a/src/ia32/codegen-ia32.cc b/src/ia32/codegen-ia32.cc
index 58eead772b067f9c5f550b0b53b2d18ba9d90f92..0759bc4787f349d875adadb61947a1ef006e539e 100644
--- a/src/ia32/codegen-ia32.cc
+++ b/src/ia32/codegen-ia32.cc
@@ -563,7 +563,7 @@ void StringCharLoadGenerator::Generate(MacroAssembler* masm,
     __ Assert(zero, "external string expected, but not found");
   }
   __ mov(result, FieldOperand(string, ExternalString::kResourceDataOffset));
-  // Assert that the external string has not been finalized yet.
+  // Assert that the data pointer cache is valid.

[Lasse Reichstein, 2011/11/24 09:21:42]

This shouldn't be necessary any more, right?
The cache, if it is there, is always valid.
Perhaps put this inside 'if (FLAG_debug_code) {' and make it a real Assert.

   __ test(result, result);
   __ j(zero, call_runtime);
   Register scratch = string;