[8u] RFR 8180032 Unaligned pointer dereference in ClassFileParser

[Dmitry Cherepanov]

Please review the following backport for 8u.

JBS: https://bugs.openjdk.java.net/browse/JDK-8180032
Original: http://hg.openjdk.java.net/jdk10/jdk10/hotspot/rev/4b93e1b1d5b7
Webrev: http://cr.openjdk.java.net/~dcherepanov/openjdk8u/8180032/webrev.v0/

The original patch does not apply cleanly. Here's the list of additional 
changes for this backport patch.

src/cpu/aarch64/vm/bytes_aarch64.hpp
src/cpu/arm/vm/bytes_arm.hpp
src/cpu/s390/vm/bytes_s390.hpp

The files above are missing in 8u, the changes ignored.

src/share/vm/classfile/classFileParser.cpp
src/share/vm/classfile/classFileParser.hpp
src/share/vm/classfile/classFileStream.hpp

There was a cleanup in the hotspot files. It's done by 
https://bugs.openjdk.java.net/browse/JDK-8140485 which seems to be too 
massive to be backported and seems redundant. The patch for JDK-8140485 
changed the context in 10 (e.g. added const modifier) so I manually 
re-applied the changes.

src/share/vm/utilities/bytes.hpp

This umbrella header was added in 9 by 
https://bugs.openjdk.java.net/browse/JDK-8049325. This patch also seems 
optional for this backport. So I backport'ed only relevant parts (added 
bytes.hpp and updated #include directives in affected files) to 8u as a 
part of this change.

Built on Win/Mac/Linux/Solaris. Running hotspot runtime regression tests 
doesn't reveal any issue, full regression testing is in progress.

Thanks,

Dmitry