[llvm] [Timers] Add a flag to set a minimum timer value for printing (PR #139306)

[Alan Zhao via llvm-commits]

alanzhao1 wrote:

> This seems to duplicate the logic between `PrintQueuedTimers` and `printJSONValues`. Maybe the filtering could happen in `prepareToPrintList` instead?
> 
> But more generally, is this the most useful way of limiting the output size? It seems the output size with a certain timer cutoff could vary a lot depending on how long the compilation ran for example. Maybe a flag to only print the top-N timers would be more useful?

This seems like something that requires more discussion; I created a thread on Discourse: https://discourse.llvm.org/t/timers-ideas-for-truncating-the-output-of-ftime-report-and-ftime-report-json/86723

https://github.com/llvm/llvm-project/pull/139306