hg: amber/amber: manual merge with jep-334 branch

[vicente.romero at oracle.com]

Changeset: 86d506754fe0
Author:    vromero
Date:      2018-06-14 20:27 -0700
URL:       http://hg.openjdk.java.net/amber/amber/rev/86d506754fe0

manual merge with jep-334 branch

! src/java.base/share/classes/java/lang/constant/ConstantDescs.java
! test/jdk/java/lang/constant/CondyRefTest.java
! test/jdk/java/lang/constant/MethodHandleRefTest.java