[svn r374] Move label target basic block from AST to IRFunction. This is a first step to allowing labels to be emitted multiple times. (for instance within finally blocks)

module scope3;
extern(C) int printf(char*, ...);
void main()
{
    int i;
    while (i < 10) {
        scope(success) i++;
    }
    printf("%d\n", i);
}