0.8.18.25:

0.8.18.25:
	Improvements to the statistical profiler.
        * Add support for x86-64.
        * Time spent in foreign functions was previously attributed to
          "elsewhere". Now reported individually for all of them, and
          "foreign function __open", "foreign function sin", etc.
        * Walk the call stack to a depth of 8 instead of relying only
          on the PC and RA from os-context-t (currently only on x86/x86-64).
          Thus instead of just knowing that a lot of time is being spent
          on (for example) bignum operations, we might find out where
	  the bignum operations are being initiated.
        * Add a column for accrued time to the flat report.
        * Add kludgy workaround for invalid frame-pointers in the
          os-context-t structure causing segfaults.