perf report: Adjust column width to the values sampled

perf report: Adjust column width to the values sampled

Auto-adjust column width of perf report output to the
longest occuring string length.

Example:

[acme@doppio pahole]$  perf report --sort comm,dso,symbol | head -13

    12.79%   pahole  /usr/lib64/libdw-0.141.so    [.] __libdw_find_attr
     8.90%   pahole  /lib64/libc-2.10.1.so        [.] _int_malloc
     8.68%   pahole  /usr/lib64/libdw-0.141.so    [.] __libdw_form_val_len
     8.15%   pahole  /lib64/libc-2.10.1.so        [.] __GI_strcmp
     6.80%   pahole  /lib64/libc-2.10.1.so        [.] __tsearch
     5.54%   pahole  ./build/libdwarves.so.1.0.0  [.] tag__recode_dwarf_type
[acme@doppio pahole]$

[acme@doppio pahole]$  perf report --sort comm,dso,symbol -d /lib64/libc-2.10.1.so | head -10

    21.92%   pahole  /lib64/libc-2.10.1.so  [.] _int_malloc
    20.08%   pahole  /lib64/libc-2.10.1.so  [.] __GI_strcmp
    16.75%   pahole  /lib64/libc-2.10.1.so  [.] __tsearch
[acme@doppio pahole]$

Also add these extra options to control the new behaviour:

  -w, --field-width

Force each column width to the provided list, for large terminal
readability.

  -t, --field-separator:

Use a special separator character and don't pad with spaces, replacing
all occurances of this separator in symbol names (and other output) with
a '.' character, that thus it's the only non valid separator.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090711014728.GH3452@ghostprotocols.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>