Add intrinsics.procedure_of

```odin
foo :: proc(x: $T) { fmt.println(x) }
bar :: intrinsics.procedure_of(foo(int(123))) // parameters are never ran at compile time, similar to `size_of`
bar(333) // prints 333
```

src/checker.cpp

@@ -1479,6 +1479,10 @@ gb_internal Entity *entity_of_node(Ast *expr) {
 	case_ast_node(cc, CaseClause, expr);
 		return cc->implicit_entity;
 	case_end;
+
+	case_ast_node(ce, CallExpr, expr);
+		return ce->entity_procedure_of;
+	case_end;
 	}
 	return nullptr;
 }