Multiply-named variables cause problems in pic14

Variables are stored in a hash table during compilation
by the function newReg() and subsequently retrieved by
the function dirregWithName() during the stage which
inserts bank select code. However newReg() specifically
looks for multiply named variables, and if it finds a
variable at a fixed address which is already stored
under another name, it ignores the request. When the
variable is requested using dirregWithName() (by the
second name) to get bank information, it is returned
not found and the bank selection is not done.

This patch simply removes the check for duplicate name.
I'm new to this code so it should be checked at the
very least by someone who understands why the duplicate
name was put there in the first place.