Handle NaN value storing in Uint8Clamped typed arrays.

TEST=mjsunit/external-array
BUG=
R=dslomov@chromium.org

Review URL: https://codereview.chromium.org/667113002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24766 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects-inl.h

@@ -4173,7 +4173,8 @@ typename Traits::ElementType FixedTypedArray<Traits>::from_double(
 
 template<> inline
 uint8_t FixedTypedArray<Uint8ClampedArrayTraits>::from_double(double value) {
-  if (value < 0) return 0;
+  // Handle NaNs and less than zero values which clamp to zero.
+  if (!(value > 0)) return 0;
   if (value > 0xFF) return 0xFF;
   return static_cast<uint8_t>(lrint(value));
 }