They will be used by perf top, so that we have just one set of routines
to do annotation.

Rename "struct sym_priv" to "struct annotation", etc, to clarify this
code a bit.

Rename "struct sym_ext" to "struct source_line", to give it a meaningful
name, that clarifies that it is a the result of an addr2line call, that
is sorted by percentage one particular source code line appeared in the
annotation.

And since we're moving things around also rename 'sym_hist->ip' to
'sym_hist->addr' as we want to do data structure annotation at some
point.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>