Profiler can print bad values for "self" on first row

The sprintf formatting on the first line of profile data is messed up sometimes. I think it's somehow printing 0 as the "nested" value (incorrectly) and then printing the actually nested size as a value that's somehow negated digit-by-digit, in the "self" column. (notice that the digits in that self value match the "nested" for the row below, which would make since if the two rows had the same "nested" value, as is often the case.)

I've only seen this happen on the very first row.

  *                                                     nested        self    self %     count
  func #1444                                         0.000000s0.00-1-7-4-8s    0.000%         1
    func #1380                                       0.001748s   0.000006s    0.000%         1
      func #776                                      0.001538s   0.000017s    0.000%         1
        func #780                                    0.000445s   0.000004s    0.000%         1
          func #279                                  0.000274s   0.000001s    0.000%         1
            func #1300                               0.000273s   0.000002s    0.000%         1
              func #271                              0.000271s   0.000005s    0.000%         1
                func #268                            0.000263s   0.000001s    0.000%         1
                  func #311                          0.000260s   0.000003s    0.000%         1
                    func #315                        0.000256s   0.000006s    0.000%         1
                      func #317                      0.000242s   0.000002s    0.000%         1
                        func #552                    0.000237s   0.000000s    0.000%         1
                          func #1386                 0.000237s   0.000001s    0.000%         1
                            func #553                0.000236s   0.000001s    0.000%         1
                              func #558              0.000230s   0.000011s    0.000%         1

My invoking command was this:

/wizard-engine/bin/wizeng.x86-64-linux --ext:stack-switching --monitors=profile --colors=false y.wasm 10 10

Reproduce the profile output with the shown wizard-engine command and the --monitors=profile option. Trace the profiler's first-row sprintf formatting and compare its nested and self values with subsequent rows. Done means the first row prints the correct values with valid formatting, without affecting the remaining profile rows.