def locate_line_in_cm(line, cm=self)
      cm.lines.each_with_index do |l, i|
        next unless (i&1 == 1)
        if (l ==  line)
          # Found target line - return first IP
          return cm.lines[i-1]
        elsif l > line
          return nil
        end
      end
      return nil
    end
def locate_line_in_cm(line, cm=self)
      cm.lines.each_with_index do |l, i|
        next unless (i&1 == 1)
        if (l ==  line)
          # Found target line - return first IP
          return cm.lines[i-1]
        elsif l > line
          return nil
        end
      end
      return nil
    end
FIXME: until the next two routines find their way back into
 Rubinius::CompiledMethod...

 Locates the instruction address (IP) of the first instruction on
 the specified line if is in CompiledMethod cm only, or nil if no
 match for the specified line is found.

 @return [Fixnum, NilClass] returns
   nil if nothing is found, else the first IP for the line