bug: void expression as function argument

### Description
CCC compiles code where a `void` expression is passed as a function argument without producing a diagnostic.

### Reproducer
``` c
#include

void void_fn() {
printf("Hello, World!\n");
}

int main() {
printf("%d\n", void_fn());
return 0;
}
```

### Expected Behavior
The C language specification on function calls (C11 6.5.2.2 paragraph 2) states that:
> Each argument shall have a type such that its value may be assigned to an object with the unqualified version of the type of its corresponding parameter

As void does not have a value, this should produce a diagnostic.
Clang and GCC both produce an error:
`error: invalid use of void expression`

### Actual Behavior
CCC compiles silently and produces a binary.
Executing the binary will print:
```
Hello, World!
14
```
The integer printed by `main` is the length of the string printed by `void_fn`.