correct fix for aliasing bugs

[Jack Howarth]

Steve,
    Xplor-nih has a lot of legacy code from the 80's (I've been trying
to fix odds and ends like getting rid of arithmetic IF statements).
Also the program gets lots of donated code from various NMR labs so
the coding practices vary a lot. 
   I am wondering however why we can't have a compiler warning for this.
Is it really that hard for the preprocessor to warn if the same variable
appears twice in a function or subroutine call? Certainly would make my
life simplier in trying to find all of these.
                Jack