Line number bug (not shared nodes related)

Imported from http://bugzilla.roxen.com/bugzilla/show_bug.cgi?id=2726

Reported by Martin Stjernholm mast@roxen.com

In this program, Pike reports the error on the line indicated with the comment:

    mixed foo;
    array bar = ({});

    int main()
    {
      int i = 1;
      if (i) {
	foo = bar[i];
      }
    } // Attempt to index the empty array with 1.

The problem is the same whether or not shared nodes are enabled. It's interesting that the problem disappears if the variable i isn't function local, or if bar is replaced by a literal ({}) but not if it's made constant.

The problem does not exist in 7.2 and earlier. Tested in a Pike compiled without machine code.