add command line option to disable profiling

[poscat0x04]

Right now nixpkgs defaults to enable profiling.

[peti]

Please use any of these flags:

  --enable-library-profiling
                           enable library profiling in the generated build
  --enable-executable-profiling
                           enable executable profiling in the generated build
  --enable-profiling       enable both library and executable profiling in the
                           generated build

[poscat0x04]

I know I could use those flags to enable profiling. What I'm asking are flags to disable profiling.

[peti]

I see. Sorry, I misunderstood your request at first.