GMP and MPFR are no longer a sub-component of gcc (config-wise).
Build and install GMP and MPFR for the target.
Use the target GMP and MPFR to build the native gdb.
Have separate extra_config for cross gdb, native gdb and gdbserver.
Check native GMP and MPFR in //.

/trunk/scripts/build/debug/300-gdb.sh | 27 19 8 0 ++++++++++++++++-------
/trunk/scripts/build/gmp.sh | 47 39 8 0 ++++++++++++++++++++++++++++++++-------
/trunk/scripts/build/mpfr.sh | 49 40 9 0 +++++++++++++++++++++++++++++++++--------
/trunk/steps.mk | 2 2 0 0 ++
/trunk/config/cc/gcc.in | 18 1 17 0 +--------------
/trunk/config/debug/gdb.in | 6 1 5 0 +----
/trunk/config/config.in | 1 1 0 0 +
/trunk/config/gmp_mpfr.in | 34 34 0 0 ++++++++++++++++++++++++++++
8 files changed, 137 insertions(+), 47 deletions(-)

 # Kernel options

 menu "Kernel"

 choice

     bool

     prompt "Target OS"

     default KERNEL_LINUX

 config KERNEL_LINUX

     bool

     prompt "linux"

     help

       Build a toolchain targeting systems running Linux as a kernel.

 endchoice

 config KERNEL_VERSION

     string

 if KERNEL_LINUX

 source config/kernel/linux.in

 endif

 endmenu