Remove unnecessary environment from LStoreKeyedFastElements.

src/x64/lithium-codegen-x64.cc

Index: src/x64/lithium-codegen-x64.cc
===================================================================
--- src/x64/lithium-codegen-x64.cc	(revision 10299)
+++ src/x64/lithium-codegen-x64.cc	(working copy)
@@ -3200,13 +3200,6 @@
   Register elements = ToRegister(instr->object());
   Register key = instr->key()->IsRegister() ? ToRegister(instr->key()) : no_reg;
 
-  // This instruction cannot handle the FAST_SMI_ONLY_ELEMENTS -> FAST_ELEMENTS
-  // conversion, so it deopts in that case.
-  if (instr->hydrogen()->ValueNeedsSmiCheck()) {
-    Condition cc = masm()->CheckSmi(value);
-    DeoptimizeIf(NegateCondition(cc), instr->environment());
-  }
-
   // Do the store.
   if (instr->key()->IsConstantOperand()) {
     ASSERT(!instr->hydrogen()->NeedsWriteBarrier());