SIGSEV with proc of var result returning nothing

[Wh1teDuke]

Test

proc foo: var int = discard
let f = foo()

Result: SIGSEGV: Illegal storage access. (Attempt to read from nil?)

I would expect the compiler to be able to catch situations like this (or a clearer error message).

---

> nim -v
Nim Compiler Version 0.13.1 (2016-04-04) [Windows: i386]
Copyright (c) 2006-2016 by Andreas Rumpf

git hash: 147961d0069ed434796eed9ceacf52914087f789
active boot switches: -d:release

[Araq]

See also bug #124

[Araq]

Now produces:

temp.nim(2, 21) Warning: Cannot prove that 'result' is initialized. This will become a compile time error in the future.