perf tools: Support full source file paths for srcline

perf tools: Support full source file paths for srcline

For perf report/script srcline currently only the base file name of the
source file is printed. This is a good default because it usually fits
on the screen.

But in some cases we want to know the full file name, for example to
aggregate hits per file.

In the later case we need more than the base file name to resolve file
naming collisions: for example the kernel source has ~70 files named
"core.c"

It's also useful as input to post processing tools which want to point
to the right file.

Add a flag to allow full file name output.

Add an option to perf report/script to enable this option.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1438986245-15191-1-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>