Revert "Harden NumberToSize against overflows."

This reverts commit r17733 for breaking Linux build.

TBR=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/69243005

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17734 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/v8conversions.h

@@ -60,15 +60,10 @@ inline size_t NumberToSize(Isolate* isolate,
                            Object* number) {
   SealHandleScope shs(isolate);
   if (number->IsSmi()) {
-    int value = Smi::cast(number)->value();
-    CHECK_GE(value, 0);
-    ASSERT(Smi::kMaxValue <= std::numeric_limits<size_t>::max());
-    return static_cast<size_t>(value);
+    return Smi::cast(number)->value();
   } else {
     ASSERT(number->IsHeapNumber());
     double value = HeapNumber::cast(number)->value();
-    CHECK(value >= 0 &&
-          value <= std::numeric_limits<size_t>::max());
     return static_cast<size_t>(value);
   }
 }