hg: amber/amber: additional syncing with the latest spec

[vicente.romero at oracle.com]

Changeset: dc313d4aad10
Author:    vromero
Date:      2020-02-13 14:05 -0500
URL:       https://hg.openjdk.java.net/amber/amber/rev/dc313d4aad10

additional syncing with the latest spec
checking that there are no duplicates in the permits list
checking that subtypes listed in the permits list have the sealed type as a direct supertype
checking that sealed and super are in same package if in unnamed module or in same module in other case
checking that type variables are not listed in the permits clause
checking that a sealed type has at least one subtype

! src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java
! src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties
! src/jdk.compiler/share/classes/com/sun/tools/javac/tree/TreeInfo.java
! test/langtools/tools/javac/sealed/SealedCompilationTests.java
! test/langtools/tools/javac/sealed/SealedDiffConfigurationsTest.java