The first two lines here are now familiar: the first adds the "merge"
block to the Function object (it was previously floating, like the else
-block above). The second block changes the insertion point so that newly
+block above). The second changes the insertion point so that newly
created code will go into the "merge" block. Once that is done, we need
to create the PHI node and set up the block/value pairs for the PHI.