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?

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   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