3432 – ICE(e2ir.c): casting template expression

void main() {
 void fun(T)() {}
 int x = cast(int)fun;
}
----
fun(T)
Internal error: e2ir.c 644

Oops, local template functions seem to be legal in D2. I didn't realize that. So this is valid code.

Applies to D1 as well. Doesn't require nested templates. Test case (ICEs even on DMD0.175):
---
void fun(T=int)(int w, int z) {}
void main() {
 auto x = cast(void function(int, int))fun;
}
---
Root cause: Shouldn't be able to cast from void to anything else (except void).
This patch also moves some error messages from e2ir into the front-end where they belong.
-----
PATCH: expression.c, line 7423 (DMD 2.035, svn rev215):
	if (!to->equals(e1->type))
	{
	 e = op_overload(sc);
	 if (e)
	 {
		return e->implicitCastTo(sc, to);
	 }
+	 /* Cannot cast from void to anything other than void
+	 */
+	 if (e1->type == Type::tvoid) {
+		error("'%s' is void and cannot be cast to %s", e1->toChars(), to->toChars());
+		return new ErrorExp();
+	 }
	}
	Type *t1b = e1->type->toBasetype();
	Type *tob = to->toBasetype();

SVN commit: http://www.dsource.org/projects/dmd/changeset/232 

Fixed dmd 1.051 and 2.036