mesa: Import improvements from latest oe-core

:Release Notes:
There were few fixes and cleanup in oe-core which
will further simplify our .bbappend.

:Detailed Notes:
Take advantage of this patchset:
http://lists.openembedded.org/pipermail/openembedded-core/2013-July/080589.html

:Testing Performed:
Tested in VirtualBox.

:QA Notes:
Affects only emulator builds

:Build Notes:
Must go in with
https://gpro.palm.com/7003

:Issues Addressed:
[GF-35765] Update mesa and llvm in meta-webos-backports from latest
           oe-core and meta-oe

Open-webOS-DCO-1.0-Signed-off-by: Martin Jansa <martin.jansa@lge.com>
Change-Id: Ib0599d1ef07c8bccf39a2aa628ee25923acc5fe7
Reviewed-on: https://g2g.palm.com/2898
Reviewed-by: Martin Jansa <Martin.Jansa@lge.com>
Tested-by: Martin Jansa <Martin.Jansa@lge.com>
Reviewed-by: Susan Montooth <susan.montooth@lge.com>