8134538: Duplicate implementations of os::lasterror

[patricio.chilano.mateo at oracle.com]

Hi all,

Could you please review this small change?

Summary: Identical Linux, BSD, Solaris and AIX implementations of 
os::lasterror were replaced with a single os_posix one.

Bug URL: https://bugs.openjdk.java.net/browse/JDK-8134538
Webrev 
URL:http://cr.openjdk.java.net/~coleenp/8134538.01/webrev/index.html 
<http://cr.openjdk.java.net/%7Ecoleenp/8134538.01/webrev/index.html>

The fix was tested with Mach5 on tiers 1-5 on all platforms.

Thanks,
Patricio