HoistLocalArraysTrans could rename in face of clash

[arporter]

Simon has reported:

If variables with identical names are declared in more than one procedure of a module and at least one of them is an automatic array, then the transformation fails due to a name clash. To avoid this, hoisted symbols could be uniquely renamed.

This should be a relatively simple extension although we'll have to check for any CodeBlocks in the routine from which the array is being hoisted.