Changing string length field type from int to SMI. It will make it be a regu...

src/x64/stub-cache-x64.cc

Index: src/x64/stub-cache-x64.cc
===================================================================
--- src/x64/stub-cache-x64.cc	(revision 4579)
+++ src/x64/stub-cache-x64.cc	(working copy)
@@ -327,8 +327,7 @@
   GenerateStringCheck(masm, receiver, scratch1, miss, &check_wrapper);
 
   // Load length directly from the string.
-  __ movl(rax, FieldOperand(receiver, String::kLengthOffset));
-  __ Integer32ToSmi(rax, rax);
+  __ movq(rax, FieldOperand(receiver, String::kLengthOffset));
   __ ret(0);
 
   // Check if the object is a JSValue wrapper.
@@ -340,8 +339,7 @@
   // directly if it is.
   __ movq(scratch2, FieldOperand(receiver, JSValue::kValueOffset));
   GenerateStringCheck(masm, scratch2, scratch1, miss, miss);
-  __ movl(rax, FieldOperand(scratch2, String::kLengthOffset));
-  __ Integer32ToSmi(rax, rax);
+  __ movq(rax, FieldOperand(scratch2, String::kLengthOffset));
   __ ret(0);
 }