MIPS: Tag smi-constants as smi. This also fixes code that copies holes into arrays.

Port r14814 (8a28ccfb)

BUG=

Review URL: https://codereview.chromium.org/16041005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14830 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mips/lithium-codegen-mips.cc

@@ -506,7 +506,7 @@ Handle<Object> LCodeGen::ToHandle(LConstantOperand* op) const {
 
 
 bool LCodeGen::IsInteger32(LConstantOperand* op) const {
-  return chunk_->LookupLiteralRepresentation(op).IsInteger32();
+  return chunk_->LookupLiteralRepresentation(op).IsSmiOrInteger32();
 }