[Lazarus] CFI in FpDebug

[Joost van der Sluis]

Hi all,

I've just pushed a commit that changed the stack-unwinding logic for 
FpDebug.

What is new is that when the executable includes Call Frame Information 
(CFI) as specified by the Dwarf-format and CFI is available for the a 
certain location, the CFI is used to unwind the stack. (x86_64 and i386 
only)

Note however, that the CFI generated by FPC is not always correct, but 
in those cases is should fallback to the old implementation.

In principle things could only get better. But if not, please tell me.

Regards,

Joost.