MIPS: ARM: fix a bug with saving lr register in GenerateSmiToDouble.

Port r13107 (63aea0a3)

BUG=
TEST=

Review URL: https://codereview.chromium.org/11574013
Patch from Akos Palfi <palfia@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13258 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/codegen-mips.cc

@@ -246,7 +246,7 @@ void ElementsTransitionGenerator::GenerateSmiToDouble(
                       HeapObject::kMapOffset,
                       a3,
                       t5,
-                      kRAHasBeenSaved,
+                      kRAHasNotBeenSaved,
                       kDontSaveFPRegs,
                       OMIT_REMEMBERED_SET,
                       OMIT_SMI_CHECK);