ARM: Fix register name in AllocateAsciiConsString.

BUG=
R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/15024004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14601 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/macro-assembler-arm.cc

@@ -1939,7 +1939,7 @@ void MacroAssembler::AllocateAsciiConsString(Register result,
   ExternalReference high_promotion_mode = ExternalReference::
       new_space_high_promotion_mode_active_address(isolate());
   mov(scratch1, Operand(high_promotion_mode));
-  ldr(scratch1, MemOperand(r4, 0));
+  ldr(scratch1, MemOperand(scratch1, 0));
   cmp(scratch1, Operand::Zero());
   b(eq, &allocate_new_space);