Bug: CTW fails compiling java/util/Base64$Encode

[Roland Westrelin]

>   http://cr.openjdk.java.net/~shade/shenandoah/fix-base64.patch

That looks good to me. Can you send it for review upstream?

> (Not very sure must_be_not_null is needed; inspecting the Java code shows that intrinsified method
> is always called with non-null src/dst)

must_be_not_null tells the compiler we know src/dst are not null
eventhough there are no null checks. So I think the fix should include
them.

Roland.