Eliminate overflow check for non-overflowing smi << operations.

runtime/vm/intermediate_language_arm.cc

Index: runtime/vm/intermediate_language_arm.cc
===================================================================
--- runtime/vm/intermediate_language_arm.cc	(revision 37537)
+++ runtime/vm/intermediate_language_arm.cc	(working copy)
@@ -2857,7 +2857,7 @@
 
 static void EmitSmiShiftLeft(FlowGraphCompiler* compiler,
                              BinarySmiOpInstr* shift_left) {
-  const bool is_truncating = shift_left->is_truncating();
+  const bool is_truncating = shift_left->IsTruncating();
   const LocationSummary& locs = *shift_left->locs();
   const Register left = locs.in(0).reg();
   const Register result = locs.out(0).reg();
@@ -2976,7 +2976,7 @@
     }
   } else if (op_kind() == Token::kMOD) {
     num_temps = 2;
-  } else if (((op_kind() == Token::kSHL) && !is_truncating()) ||
+  } else if (((op_kind() == Token::kSHL) && !IsTruncating()) ||
              (op_kind() == Token::kSHR)) {
     num_temps = 1;
   } else if ((op_kind() == Token::kMUL) &&
@@ -3009,7 +3009,7 @@
   }
   summary->set_in(0, Location::RequiresRegister());
   summary->set_in(1, Location::RegisterOrSmiConstant(right()));
-  if (((op_kind() == Token::kSHL) && !is_truncating()) ||
+  if (((op_kind() == Token::kSHL) && !IsTruncating()) ||
       (op_kind() == Token::kSHR)) {
     summary->set_temp(0, Location::RequiresRegister());
   }
@@ -3031,7 +3031,6 @@
     return;
   }
 
-  ASSERT(!is_truncating());
   const Register left = locs()->in(0).reg();
   const Register result = locs()->out(0).reg();
   Label* deopt = NULL;