Power8 fusion of addis,addi

[Joel Brobecker]

Hi Alan,

> gdb/
> 	* ppc64-tdep.c (ppc64_standard_linkage8): New.
> 	(ppc64_skip_trampoline_code): Recognise ELFv2 stub supporting fusion.

OK for the GDB part.

Thanks! :)
-- 
Joel