Hi...

When single stepping a 64bit windows application gdb at present does not 
step into
functions residing in a dll. This is due to the fact that handling of 
dll trampoline code
for win64 is missing.

I added a new function to amd64-windows-tdep.c to handle this similar to 
the existing function (i386_pe_skip_trampoline_code()). With some 
differences:

- On 32bit windows dll trampoline code is expressed as jmp *(dest) while on
   64bit windows this is expressed as jmp *<offset>(%rip). Took care of 
this.
- The jump destination is on 64bit windows of course 8 byte long. I 
could not
   find a function that transforms this into a CORE_ADDR like 
read_memory_unsigned_integer()
   it is doing in the 32bit case.  So I did the transformation on my 
own. While this is
   high performant it might not be the "official" gdb way. If someone 
can give me a
   hint on how to the transformation the "official" way I will adjust my 
patch - if wished.

Now single stepping into dll code works.

ChangeLog:

2012-03-14  Roland Schwingel<roland.schwingel@onevision.com>

         * amd64-windows-tdep.c: #include "frame.h"
         (amd64_windows_skip_trampoline_code): New function.
	(amd64_windows_init_abi): Add trampoline registration.

Roland