[patch] Deal with larger anti-ranages in compare_range_with_value

[Tom Truscott]

Somewhat related to this (EQ/NE working the same way,
it looks like the ordinary-range NE test is missing
the case of [p,p] != q  detected by compare_values (p,q) returning +2

Perhaps the EQ_EXPR and NE_EXPR code on approx lines 1714..1747
could be merged.  Change the separate ifs into:

  if (comp == EQ_EXPR || comp == NE_EXPR)
    {
      ...
          if (cmp == 0)
            return comp == EQ_EXPR ? boolean_true_node : boolean_false_node;

and so on.

Tom Truscott