dip1000 and preview in combine to cause extra safety errors

[Walter Bright]

On 6/8/2022 3:03 PM, Dukc wrote:
> In fact, I'm surprised the compiler does not siletly add `return`.
D does not do attribute inference for regular functions, because of the risk of 
a mismatch between a function's definition (with body) and a declaration 
(without body) of the same function.