[perl #126016] Rat.Str incorrectly rounds in the part after the decimal dot

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# New Ticket Created by  Moritz Lenz 
# Please include the string:  [perl #126016]
# in the subject line of all future correspondence about this issue. 
# <URL: https://rt.perl.org/Ticket/Display.html?id=126016 >


14:16 < moritz> m: say 0.9999999999999999999999.Str
14:16 <+camelia> rakudo-moar cbf85b: OUTPUT«0.10␤»

Clearly this is wrong. If the intent is to round up, it should produce 
1.0, not 0.10.

The Rat object itself is constructed correctly:

14:16 < moritz> m: say 0.9999999999999999999999.nude
14:16 <+camelia> rakudo-moar cbf85b: OUTPUT«(9999999999999999999999
                  10000000000000000000000)␤»