RFR: 8242244: Remove redundant ELF machine definitions

[John Paul Adrian Glaubitz]

Hi!

Please review this small change which removes redundant ELF machine
definitions for EM_AARCH64 and EM_486 on Linux and Solaris [1].

Both EM_AARCH64 and EM_486 are defined by the kernel headers on both
Solaris 11.3 or higher (verified on gcc211.fsffrance.org) and Linux 3.12
or higher [2], so I think it's safe to remove those definitions from
the JDK codebase unless the JDK is supposed to be built on systems
older than that.

Thanks,
Adrian

> [1] http://cr.openjdk.java.net/~glaubitz/8242244/webrev.01/
> [2] https://elixir.bootlin.com/linux/v3.12/source/include/uapi/linux/elf-em.h

-- 
 .''`.  John Paul Adrian Glaubitz
: :' :  Debian Developer - glaubitz at debian.org
`. `'   Freie Universitaet Berlin - glaubitz at physik.fu-berlin.de
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