Implement date library functions in C++.

src/runtime.h

Index: src/runtime.h
diff --git a/src/runtime.h b/src/runtime.h
index bd6568f45e4ff81b67422868a88716cfd4371ee9..273b36133fdf73d6d544a1ec1a9902486d62e0f9 100644
--- a/src/runtime.h
+++ b/src/runtime.h
@@ -246,10 +246,9 @@ namespace internal {
   F(DateCurrentTime, 0, 1) \
   F(DateParseString, 2, 1) \
   F(DateLocalTimezone, 1, 1) \
-  F(DateLocalTimeOffset, 0, 1) \
-  F(DateDaylightSavingsOffset, 1, 1) \
+  F(DateToUTC, 1, 1) \
   F(DateMakeDay, 2, 1) \
-  F(DateYMDFromTime, 2, 1) \
+  F(DateSetValue, 3, 1) \
   \
   /* Numbers */ \
   \
@@ -493,6 +492,7 @@ namespace internal {
   F(Arguments, 1, 1)                                                         \
   F(ValueOf, 1, 1)                                                           \
   F(SetValueOf, 2, 1)                                                        \
+  F(DateField, 2 /* date object, field index */, 1)                \
   F(StringCharFromCode, 1, 1)                                                \
   F(StringCharAt, 2, 1)                                                      \
   F(ObjectEquals, 2, 1)                                                      \