Now use a named variable as the one of an alias clique to autodestroy.
Now use a named variable as the one of an alias clique to autodestroy.

We were using the last member of an alias clique in the autoDestroy, but one test case
(hpl-blc.chpl) was failing due to code like this
  call_tmp4 = foo();
  col = bar(call_tmp4);
  if (cond)
  {
    ...
    autodestroy(call_tmp4)
    autodestroy(T2);
    goto _lbl_end;
  }
  T2 = col; //oops!
Using the named variable in place of the temporary solves this.  No tests regressed as a
result of this change.

Now at 197 > 41 > 7.

hildeth/chapel,hildeth/chapel,hildeth/chapel,hildeth/chapel,hildeth/chapel,hildeth/chapel,hildeth/chapel