profiling: allow configuring minimum display threshold for hotpath

statprof.display_hotpath() accepts a "limit" function to choose the
minimum threshold for samples to display. The default is 0.05, which
means you don't need individual items contributing less than 5%.

I had a need to adjust this threshold. We already have a config
option for it. So let's reuse it.

check-config.py doesn't like having multiple defaults for the
ui.configwith() calls. The behavior is obviously correct. I'm
not sure if it is worth teaching check-config.py how to ignore
this. So I've just accepted the new output.

mercurial/help/config.txt

@@ -1580,6 +1580,7 profiling is done using lsprof.
 
     Only used by the ``stat`` profiler.
 
+    For the ``hotpath`` format, default is ``0.05``.
     For the ``chrome`` format, default is ``0.005``.
 
     The option is unused on other formats.

mercurial/profiling.py

@@ -138,6 +138,9 def statprofile(ui, fp):
             showmin = ui.configwith(fraction, 'profiling', 'showmin', 0.005)
             showmax = ui.configwith(fraction, 'profiling', 'showmax', 0.999)
             kwargs.update(minthreshold=showmin, maxthreshold=showmax)
+        elif profformat == 'hotpath':
+            limit = ui.configwith(fraction, 'profiling', 'showmin', 0.05)
+            kwargs['limit'] = limit
 
         statprof.display(fp, data=data, format=displayformat, **kwargs)
 

tests/test-check-config.t

@@ -33,3 +33,6 New errors are not allowed. Warnings are
 
   $ hg files "set:(**.py or **.txt) - tests/**" | sed 's|\\|/|g' |
   >   python contrib/check-config.py
+              limit = ui.configwith(fraction, 'profiling', 'showmin', 0.05)
+  
+  conflict on profiling.showmin: ('with', '0.05') != ('with', '0.005')