Add x-axis to histogram

[andig]

To make the analysis for golang/go#46050 (comment) more meaningful it would be great if the x axis of the histogram could show the bin's values as mentioned in the readme.

[baiwfg2]

I agree. Somehow I cannot figure out what x axis and y axis of the histogram means, and what the bucket ranges are .

[whillas-yabble]

There is a xlab=True option in the python function version. I'm having problems with it as the labels are spaced but the histogram is not so they don't line up?

 489| o 
 463| o 
 437| o 
 412| o 
 386| oo 
 360| oo 
 335| oo 
 309| ooo 
 283| ooo 
 258| ooo 
 232| oooooo 
 206| oooooo 
 180| oooooo 
 155| ooooooo 
 129| ooooooo 
 103| ooooooo 
 78| ooooooooo 
 52| ooooooooo 
 26| ooooooooooo 
 1| oooooooooooooooooooooooo oo o o o o o
 -----------------------------------------------------------------------------------------------------
 1 4 8 1 1 2 2 2 3 3 4 4 4 5 5 6 6 6 7 7 7 8 8 9 9 9 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 
 . . 2 6 0 4 8 2 6 0 4 8 2 6 0 4 7 1 5 9 3 7 1 5 9 0 0 1 1 1 2 2 3 3 3 4 4 5 5 5 6 6 7 7 7 8 8 9 9 9 
 9 8 . . . . . . . . . . . . . . . . . . . . . . . 3 7 1 5 9 3 7 1 4 8 2 6 0 4 8 2 6 0 4 8 2 6 0 4 8 
 4 8 8 7 7 6 5 5 4 4 3 2 2 1 1 0 9 9 8 8 7 6 6 5 5 . . . . . . . . . . . . . . . . . . . . . . . . 
 2 6 4 8 2 6 4 8 2 6 4 8 2 6 4 8 2 6 4 3 3 2 2 1 0 0 9 9 8 7 7 6 6 5 4 4 3 3 2 1 1 0 

[whillas-yabble]

Would also be good to have an option to clip the tail off