hg: jdk9/hs/hotspot: 8176147: JVM should throw CFE for duplicate Signature attributes

[harold.seigel at oracle.com]

Changeset: fc60138effe1
Author:    hseigel
Date:      2017-03-08 09:04 -0500
URL:       http://hg.openjdk.java.net/jdk9/hs/hotspot/rev/fc60138effe1

8176147: JVM should throw CFE for duplicate Signature attributes
Summary: Add the needed checks to ClasFileParser for duplicate Signature attributes.
Reviewed-by: dholmes, gtriantafill

! src/share/vm/classfile/classFileParser.cpp
+ test/runtime/duplAttributes/DupSignatureAttrs.jcod
+ test/runtime/duplAttributes/TestDupSignatureAttr.java