Advent of bugfixes

Thu Dec 19 05:40:10 UTC 2019

18. day: 17 bugs were removed (issues 4473, 5872, 7865, 16375, 
17100, 17978, 18393, 18399, 18657, 19060, 19205, 19309, 20151, 
20303, 20383, 20446, 20454)

Real fixes:
Issue 20151 - particular directory layout causes DMD to crash 
with an access violation
Issue 20303 - Memory leak in core.thread
Issue 20383 - [REG 2.084.z] illegal conversion from int[] to 
ubyte[] is accepted