[win32] Fix couple of bugs in signal unwinder

[Dave Korn]

On 26/03/2010 10:05, Eric Botcazou wrote:
> Hi,
> 
> a couple of bugs have been discovered since Pascal submitted the unwinder code 
> for Win32 in 2007: the restoration of the frame pointer is incorrect (wrong 
> register number) and that of the instruction pointer is obsolete.
> 
> This patch has been in our 4.3 tree for a couple of years and is necessary 
> for proper operation in Ada.  Untested with anything newer, but nothing is 
> supposed to have changed in this area so if maintainers are interested...

  I certainly am :)  I'll give this a test spin up over the weekend.

  Do you have any testcase, or perhaps an internal PR that you could email me
a plaintext copy-paste of offlist, or documentation, that describes or
demonstrates the bug in detail?

    cheers,
      DaveK