hg: jdk/jdk13: 8226406: JVM fails to detect mismatched or corrupt CDS archive

[calvin.cheung at oracle.com]

Changeset: 7b7df2be6219
Author:    ccheung
Date:      2019-07-12 08:40 -0700
URL:       https://hg.openjdk.java.net/jdk/jdk13/rev/7b7df2be6219

8226406: JVM fails to detect mismatched or corrupt CDS archive
Summary: Check important archive header fields such as _jvm_ident before processing other fields.
Reviewed-by: iklam, jiangli

! src/hotspot/share/memory/filemap.cpp
! src/hotspot/share/prims/cdsoffsets.cpp
! test/hotspot/jtreg/runtime/appcds/SharedArchiveConsistency.java
! test/hotspot/jtreg/runtime/appcds/TestCommon.java