title: gdb stops with too many watchpoints when there is only one
body: <p>Do you know any other reasons why a watchpoint could not be inserted other than too many hardware breakpoints/watchpoints?</p>
  
  <p>I have the following debug session:</p>
  
  <pre><code>GNU gdb (GDB) 7.1
  ...
  (gdb) watch itrap_t_beg[1][222]
  Hardware watchpoint 1: itrap_t_beg[1][222]
  (gdb) cont
  Continuing.
  ...
  Hardware watchpoint 1: itrap_t_beg[1][222]
  
  ...
  (gdb) cont
  Continuing.
  Warning:
  Could not insert hardware watchpoint 1.
  Could not insert hardware breakpoints:
  You may have requested too many hardware breakpoints/watchpoints.
  
  (gdb) info break
  Num     Type           Disp Enb Address            What
  1       hw watchpoint  keep y                      itrap_t_beg[1][222]
          breakpoint already hit 1 time
  </code></pre>
  
  <p>As you can see, there's only one watchpoint yet it can't insert the breakpoint.</p>
  
  <p>Do you know how can I fix this?</p>