libc/newlib: build newlib in the proper step

Currently, newlib is built in the start_file step, which is wrong, but was
needed when the baremetal integration was... well, 'unfinished'.

Now that we build the baremetal compiler from the final cc step, and a
proper core gcc in pass-1 and pass-2, we can move the newlib build to the
step do_libc, where it belongs.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

diff -durN gcc-4.4.5.orig/gcc/config/netbsd-elf.h gcc-4.4.5/gcc/config/netbsd-elf.h

--- gcc-4.4.5.orig/gcc/config/netbsd-elf.h	2007-09-03 18:14:04.000000000 +0200

+++ gcc-4.4.5/gcc/config/netbsd-elf.h	2010-10-09 22:59:57.000000000 +0200

@@ -82,6 +82,7 @@

 #define NETBSD_LINK_SPEC_ELF \

   "%{assert*} %{R*} %{rpath*} \

    %{shared:-shared} \

+   %{symbolic:-Bsymbolic} \

    %{!shared: \

      -dc -dp \

      %{!nostdlib: \