dillon1000/react

Handle IIFE with logical mutated later

The previous changes mostly meant that we removed the label terminal and didn't 
have instructions for the same scope split in a way that we couldn't merge. But 
logicals were still causing a split because MergeConsecutiveScopes can't merge 
the blocks in that case. Here we move PruneUnusedLabels earlier in the pipeline 
to ensure that instructions from IIFEs have floated up to the parent block scope 
level.