Revert "Clusterfuzz identified overflow check needed in dehoisting."

src/hydrogen-dehoist.cc

Index: src/hydrogen-dehoist.cc
diff --git a/src/hydrogen-dehoist.cc b/src/hydrogen-dehoist.cc
index fe68e46d5aba0b435afc0791b70aed87400e40bf..fe0ae764ad63dcf3fc6c3ca625ebd90cdea7fcf7 100644
--- a/src/hydrogen-dehoist.cc
+++ b/src/hydrogen-dehoist.cc
@@ -28,23 +28,15 @@ static void DehoistArrayIndex(ArrayInstructionInterface* array_operation) {
   if (!constant->HasInteger32Value()) return;
   int32_t sign = binary_operation->IsSub() ? -1 : 1;
   int32_t value = constant->Integer32Value() * sign;
-  if (value < 0) return;
-
-  // Check for overflow.
-  int32_t shift_amount =
-      1 << ElementsKindToShiftSize(array_operation->elements_kind());
-  int32_t multiplication_result = value * shift_amount;
-  if ((multiplication_result / shift_amount) != value) return;
-  value = multiplication_result;
-
-  // Ensure that the array operation can add value to existing base offset
-  // without overflowing.
-  if (!array_operation->CanIncreaseBaseOffset(value)) return;
+  // We limit offset values to 30 bits because we want to avoid the risk of
+  // overflows when the offset is added to the object header size.
+  if (value >= 1 << array_operation->MaxBaseOffsetBits() || value < 0) return;
   array_operation->SetKey(subexpression);
   if (binary_operation->HasNoUses()) {
     binary_operation->DeleteAndReplaceWith(NULL);
   }
-  array_operation->IncreaseBaseOffset(value);
+  value <<= ElementsKindToShiftSize(array_operation->elements_kind());
+  array_operation->IncreaseBaseOffset(static_cast<uint32_t>(value));
   array_operation->SetDehoisted(true);
 }