Crash with try statement

[wenpen]

void f(){
}

void test(int x){
  try {
    f();
    if (x) {
      f();
    }
  } catch(...) {
  }
}

[bcardosolopes]

I'm going to resume exception work pretty soon, assigning to me.

[smeenai]

We're able to emit CIR for this now, but lowering still fails.

[smeenai]

This works fully now and the emitted LLVM IR looks good. We duplicate the landing pads, which I filed #1052 for, so I'm closing this out.