Ensure function hints are parenthesized.

Summary: This matches HHVM's behavior.

Reviewed By: @elgenie

Differential Revision: D1527616
Added xdebug computerized tracing output

Summary: This diff adds xdebug computerized tracing format output.

Computerized tracing output is intended to be a format that is easier to parse
programatically. More information is given and columns are simply separated by
tabs.

The specification can be found here:
http://xdebug.org/docs/execution_trace

The example given in the xdebug docs is:
    Version: 2.0.0RC4-dev
    TRACE START [2007-05-06 18:29:01]
    1   0   0   0.010870    114112  {main}  1   ../trace.php    0
    2   1   0   0.032009    114272  str_split   0   ../trace.php    8
    2   1   1   0.032073    116632
    2   2   0   0.033505    117424  ret_ord 1   ../trace.php    10
    3   3   0   0.033531    117584  ord 0   ../trace.php    5
    3   3   1   0.033551    117584
    2   2   1   0.033567    117584
    2   4   0   0.033718    117584  ret_ord 1   ../trace.php    10
    3   5   0   0.033740    117584  ord 0   ../trace.php    5
    3   5   1   0.033758    117584
    2   4   1   0.033770    117584
    2   6   0   0.033914    117584  ret_ord 1   ../trace.php    10
    3   7   0   0.033936    117584  ord 0   ../trace.php    5
    3   7   1   0.033953    117584
    2   6   1   0.033965    117584
    2   8   0   0.034108    117584  ret_ord 1   ../trace.php    10
    3   9   0   0.034130    117584  ord 0   ../trace.php    5
    3   9   1   0.034147    117584
    2   8   1   0.034160    117584
    2   10  0   0.034302    117584  ret_ord 1   ../trace.php    10
    3   11  0   0.034325    117584  ord 0   ../trace.php    5
    3   11  1   0.034342    117584
    2   10  1   0.034354    117584
    2   12  0   0.034497    117584  ret_ord 1   ../trace.php    10
    3   13  0   0.034519    117584  ord 0   ../trace.php    5
    3   13  1   0.034536    117584
    2   12  1   0.034549    117584
    1   0   1   0.034636    117584
    TRACE END   [2007-05-06 18:29:01]

Reviewed By: @ptarjan

Differential Revision: D1460615