Bug 7136 – alias this lookup should run before merging modifiers of both sides.

Test cases: void test() { struct X { Object get() immutable { return null; } alias get this; } immutable(X) x; Object y; static assert( is(typeof(1?x:y) == Object)); // fails static assert(!is(typeof(1?x:y) == const(Object))); // fails struct A { int[] get() immutable { return null; } alias get this; } immutable(A) a; int[] b; static assert( is(typeof(1?a:b) == int[])); // fails static assert(!is(typeof(1?a:b) == const(int[]))); // fails }