AssertionError in Name.compareTo

The recent changes to Name and NameTable may cause AssertionError

Name implements CharSequence, and should be usable in CharSequence.compare(CharSequence, CharSequence)

Instead, it may throw AssertionError if the names come from different name tables.

Exception in thread "main" java.lang.AssertionError
        at jdk.compiler/com.sun.tools.javac.util.Assert.error(Assert.java:155)
        at jdk.compiler/com.sun.tools.javac.util.Assert.check(Assert.java:46)
        at jdk.compiler/com.sun.tools.javac.util.Utf8NameTable$NameImpl.compareTo(Utf8NameTable.java:136)
        at jdk.compiler/com.sun.tools.javac.util.Utf8NameTable$NameImpl.compareTo(Utf8NameTable.java:73)
        at java.base/java.lang.CharSequence.compare(CharSequence.java:291)

While it maybe reasonable to check if the names are in the same table (perhaps to optimize any comparison), it should not be required.