[Windows] Work around non-monotonic clocks in the self-profiler
[Windows] Work around non-monotonic clocks in the self-profiler

On Windows, the high-resolution timestamp api doesn't seem to always be
monotonic. This can cause panics when the self-profiler uses the
`Instant` api to find elapsed time.

Work around this by detecting the case where now is less than the start
time and just use 0 elapsed ticks as the measurement.

Fixes #51648

aidancully/rust,aidancully/rust,graydon/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,graydon/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,graydon/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,graydon/rust,graydon/rust,graydon/rust,GBGamer/rust