Updated and fixed "native" support.
Updated and fixed "native" support.

- add support for MSVC compiler
- fixed cpuid toggle code
- fixed wrong ussage of feature mask register
- detect atom, core2, K10
- removed panics ...

Probably the whole detection code should be either moved into the frontend
OR at least into some extra file, so it can be reused for the amd64 and the
upcoming new x86 backends.

[r28160]

libfirm/libfirm,davidgiven/libfirm,jonashaag/libfirm,jonashaag/libfirm,8l/libfirm,8l/libfirm,MatzeB/libfirm,8l/libfirm,davidgiven/libfirm,davidgiven/libfirm,MatzeB/libfirm,jonashaag/libfirm,MatzeB/libfirm,killbug2004/libfirm,libfirm/libfirm,8l/libfirm,killbug2004/libfirm,killbug2004/libfirm,8l/libfirm,davidgiven/libfirm,davidgiven/libfirm,jonashaag/libfirm,killbug2004/libfirm,libfirm/libfirm,MatzeB/libfirm,MatzeB/libfirm,libfirm/libfirm,killbug2004/libfirm,libfirm/libfirm,davidgiven/libfirm,jonashaag/libfirm,MatzeB/libfirm,jonashaag/libfirm,killbug2004/libfirm,8l/libfirm,MatzeB/libfirm,8l/libfirm,jonashaag/libfirm,davidgiven/libfirm,killbug2004/libfirm