Compiling kernel with gcc43

[Ryan Stone]

-Wnoerror should disable it, but I don't know enough about the FreeBSD
build infrastructure to tell you where it needs to go.  Worst comes to
worst you can just delete all of the -Werrors.

Disabling -Werror will not cause any problems.  -Werror means "treat
warnings as errors".  It's very useful for development but in your
case, where you're starting with a known good source tree with no
warnings with earlier compilers, it's not necessary to have the option
enabled.  If the warnings are pointing to legitimate bugs, those bugs
also exist in a kernel built by gcc 4.2, so your kernel can't be any
worse than what you already have.