these were using were different, but with equivalent definitions.
With `ldc -O3`, the following functions now all compile to the exact same code:
{{{
int[int] y;
void foo(int x) {
if (x in y) {
auto z = x in y;
sink(*z);
}
}
void bar(int x) {
if (x in y) {
sink(y[x]);
}
}
void baz(int x) {
if (auto p = x in y) {
sink(*p);
}
}
}}}