Prevent deopt when assigning double values to typed arrays

src/assembler.h

Index: src/assembler.h
diff --git a/src/assembler.h b/src/assembler.h
index 918de62a4239c2cd5b00f2e1dafa9b0a7ad9d2c5..a88d1579462873efef8d419928abada0722b5423 100644
--- a/src/assembler.h
+++ b/src/assembler.h
@@ -64,6 +64,8 @@ class DoubleConstant: public AllStatic {
   static const double min_int;
   static const double one_half;
   static const double minus_zero;
+  static const double zero;
+  static const double uint8_max_value;
   static const double negative_infinity;
   static const double nan;
 };
@@ -625,6 +627,8 @@ class ExternalReference BASE_EMBEDDED {
   static ExternalReference address_of_min_int();
   static ExternalReference address_of_one_half();
   static ExternalReference address_of_minus_zero();
+  static ExternalReference address_of_zero();
+  static ExternalReference address_of_uint8_max_value();
   static ExternalReference address_of_negative_infinity();
   static ExternalReference address_of_nan();