New class for Date objects: caches individual date components.

test/mjsunit/fuzz-natives.js

Index: test/mjsunit/fuzz-natives.js
diff --git a/test/mjsunit/fuzz-natives.js b/test/mjsunit/fuzz-natives.js
index c4d18d041103ca7436cf08f65d5d17fa9c9c3738..b1fe87d8e37fcd49ca7b6527e045d572aa6123a0 100644
--- a/test/mjsunit/fuzz-natives.js
+++ b/test/mjsunit/fuzz-natives.js
@@ -184,8 +184,10 @@ var knownProblems = {
   "RegExpConstructResult": true,
   "_RegExpConstructResult": true,
 
-  // This function performs some checks compile time (it requires its first
-  // argument to be a compile time smi).
+  // This functions perform some checks compile time (they require one of their
+  // arguments to be a compile time smi).
+  "_DateField": true,
+  "_SetDateField": true,
   "_GetFromCache": true,
 
   // This function expects its first argument to be a non-smi.