[Timer][Statistics] Make global constructor ordering more robust

[nhaehnle]

Summary

It was observed in D129117 that the subtle dependency between statistic
and timer code is not entirely robust: the global destructor
~StatisticInfo indirectly calls CreateInfoOutputFile, which requires
the LibSupportInfoOutputFilename to not have been destructed.

By constructing LibSupportInfoOutputFilename before the StatisticInfo
object, the order of destruction is guaranteed.

[efriedma]

LGTM

[MaskRay]

llvm/lib/Support/Timer.cpp

502–503

You can use constructForStatistics while renaming.