hg: amber/amber: Improve specs, error checking, and tests for switch bootstraps

[brian.goetz at oracle.com]

Changeset: 68a36e1e6d98
Author:    briangoetz
Date:      2018-02-08 11:07 -0500
URL:       http://hg.openjdk.java.net/amber/amber/rev/68a36e1e6d98

Improve specs, error checking, and tests for switch bootstraps

! src/java.base/share/classes/java/lang/runtime/SwitchBootstraps.java
! test/jdk/java/lang/runtime/TestSwitchBootstrap.java