Now that we're using LLVM 2.5, we can stop always running the CFGSimplification pass. The pass was originally added as a workaround for a LLVM 2.4 bug where debug info would reference labels that have been optimized away.

module bug42;

void main() {
    int i = 2;
    switch (i) {
    case 0:
    case 1:
    default:
    }
}