std.conv.ConvException from double to uint64_t, but only locally in a large project

[drathier]

> ```
> std.conv.ConvException@/usr/local/opt/dmd/include/dlang/dmd/std/conv.d(2054): Value (1596) does not match any member value of enum '__c_ulonglong'
> ```
well,
```
std.conv.ConvException@/usr/local/opt/dmd/include/dlang/dmd/std/conv.d(2054): Value (42) does not match any member value of enum '__c_ulonglong'
```
but the specific value doesn't matter