[AArch64] Use selected cpu's tuning when no tuning parameter is specified

	Backport from mainline
	2014-12-11  Renlin Li  <renlin.li@arm.com>

	* config/aarch64/aarch64.c (aarch64_parse_cpu): Don't define
	selected_tune.
	(aarch64_override_options): Use selected_cpu's tuning.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_9-branch@218634 138bc75d-0d04-0410-961f-82ee72b054a4
	* doc/md.texi (Insn Lengths): Fix description of (pc).


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_9-branch@218643 138bc75d-0d04-0410-961f-82ee72b054a4
Daily bump.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_9-branch@218650 138bc75d-0d04-0410-961f-82ee72b054a4
Daily bump.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_9-branch@218696 138bc75d-0d04-0410-961f-82ee72b054a4
Merge branch 'gcc-4_9-branch' of https://github.com/gcc-mirror/gcc into 4.9.3