This is a regression issue in 2.066a git head, caused by removing object.AssociativeArray.
Test case:
int testPointerImmutable()
{
immutable x = [5 : 4];
auto aa = &x;
const(int[int])* y = aa;
// <- cast from immutable(int[int])* to const(int[int])*
return 1;
}
static assert(testPointerImmutable());
-----
test.d(6): Error: reinterpreting cast from immutable(int[int])* to const(int[int])* is not supported in CTFE
test.d(11): called from here: testPointerImmutable()
test.d(11): while evaluating: static assert(testPointerImmutable())