Add new function profiling stuff, wrap the pc_sample stuff into it.

Add new function profiling stuff, wrap the pc_sample stuff into it.

SConscript:
    Get rid of the pc_sample stuff and move to the new profiling stuff
base/traceflags.py:
    DPRINTF Stack stuff
cpu/base.cc:
cpu/base.hh:
cpu/exec_context.cc:
cpu/exec_context.hh:
cpu/simple/cpu.cc:
    Add profiling stuff
kern/kernel_stats.hh:
    Use a smart pointer
sim/system.cc:
sim/system.hh:
    Create a new symbol table that has all of the symbols for a
    particular system
util/stats/categories.py:
    change around the categories, add categories for function
    profiling stuff
util/stats/profile.py:
    No profile parsing and display code to deal with function
    profiling stuff, graph, dot, and text outputs.

--HG--
extra : convert_revision : b3de0cdc8bd468e42647966e2640ae009bda9eb8