Consistently make the bounds check for AccessArgumentsAt explicit.

src/ia32/lithium-codegen-ia32.cc

Index: src/ia32/lithium-codegen-ia32.cc
diff --git a/src/ia32/lithium-codegen-ia32.cc b/src/ia32/lithium-codegen-ia32.cc
index 296fa324bedb1e077a3a50a2eadcb28c9936ee13..32c66a05f509df7df7d7314401f628dfbdcf4e87 100644
--- a/src/ia32/lithium-codegen-ia32.cc
+++ b/src/ia32/lithium-codegen-ia32.cc
@@ -2742,12 +2742,9 @@ void LCodeGen::DoAccessArgumentsAt(LAccessArgumentsAt* instr) {
   Register length = ToRegister(instr->length());
   Operand index = ToOperand(instr->index());
   Register result = ToRegister(instr->result());
-
-  __ sub(length, index);
-  DeoptimizeIf(below_equal, instr->environment());
-
   // There are two words between the frame pointer and the last argument.
   // Subtracting from length accounts for one of them add one more.
+  __ sub(length, index);
   __ mov(result, Operand(arguments, length, times_4, kPointerSize));
 }