[kaffe] netbsd macros

[Riccardo Mottola]

Hello,

as someone might have noticed, I provided patches that uniform Netbsd's 
macro handling. The idea was suggested by a netbsd developer since 
sigcontext is causing trouble and is supported on netbsd in legacy mode. 
Signifo and ucontext are the way to go.

I found that netbsd provides some macros to access in a uniform way 
platform sensitive data: stack pointer and porgram counter. This is 
great news. If you look, that part of code in md.h is now identical 
across netbsd x86, ppc and sparc!!! I find this very clean.

the caveats are 3

1. SA_SIGNFO? Guilhem (and others) sometimes undefined it sometimes not. 
For the moment I removed his undefines. and stuck my definition in place.

2. at least one of the two macros wasn't present in older netbsd, maybe 
in even older ones both were missing. I provided replacements my copying 
in the netbsd versions for each platform. If they really work or the 
internal structures changed... that is unknown. Everyone having netbsd 
1.6 or earlier (which worked before the patches hopefully) pelase 
provide feedback.

3. what to do about platforms I didn't tacle? probably mips and 68k miss 
netbsd changes, I haven't checked if arm and sh support netbsd too. 
Should I blindly provide the same patches ?

A last note about the STACK_POINTER macro. It wasn't defined on one 
platform, if the macro is not defined in md.h, the various sources for 
jthread/pthread will provide their won version using other generic 
macros. This didn't work anymore apparently after my macros. Providi

I have verified all new macros on my own platforms. They cause no 
trouble. Indeed, on sparc they solved problems! on x86 not, but new one 
didn't pop up either.

-R