hg: jdk/jdk: 8238684: Override getOrDefault in immutable Map implementation

[claes.redestad at oracle.com]

Changeset: bc3da0226ffa
Author:    redestad
Date:      2020-02-08 15:21 +0100
URL:       https://hg.openjdk.java.net/jdk/jdk/rev/bc3da0226ffa

8238684: Override getOrDefault in immutable Map implementation
Reviewed-by: forax, psandoz, smarks

! src/java.base/share/classes/java/util/ImmutableCollections.java
! test/micro/org/openjdk/bench/java/util/ImmutableColls.java