gcc9 snapshot 20190414 is 30x slower than gcc 6.3

[Jason Mancini]

Working on getting a testcase prepared to file a bug report.  The trimmed down case shows a 6x degradation instead of 45x at -O0, but hopefully that's enough to pinpoint the reason.  (15 vs 85 seconds.)  Seems like some O(n^2) behavior, 15s becomes 90s, but 40s becomes 30m.

I used "gcc -E" to generate the output.  Is that what we're looking for here?  I'm not familiar with *.ii files (or is that the typical extension used for preprocessor output?)

Thanks!