generate callgrind output

[coke]

Parrot currently only supports profiling at the opcode level; we need to generate profiling information for everything.

From the original RT ( http://rt.perl.org/rt3/Ticket/Display.html?id=58250)

Provide a mechanism (for example, compiling with
-DPARROT_CALLGRIND)[1], that forces each Sub invocation to be reported
in a standard callgrind output
(http://valgrind.org/docs/manual/cl-format.html).

Future bonus points for providing similar support for opcodes
(probably replacing the -p option).

Double future super bonus points for combining the output of the
C-level callgrind output (available from valgrind) with the parrot sub
and opcode information into a single report.

[1] chromatic's original suggestion was an alternate runcore. I think
this suggestion makes more sense since we want this for more than
opcode dispatch, but I could be wrong.

[chromatic]

Fixed with the pluggable_runcore merge at r41801.