mknative-gcc for GCC 10 and almost all platforms. one of the
myriad of arm platforms, and the powerpc* platforms are not
yet done.

mknative-gcc for gcc 9.3.0 and amd64.

the tree has quite a number of issues to resolve before it builds.

mknative-gcc for GCC 8.3 and all ports.

first cut mknative-gcc for gcc7 amd64. i've hand edited some
libgcc files to ease mknative updates.

not functional yet.

mknative-gcc for alpha, earm, i386, mips64eb, powerpc, sparc,
sparc64, and x86-64. tree does not fully build yet, however.

first stab mknative-gcc for GCC 5.3 and amd64.

regen; backtrace support is complete

merge GCC 4.8 build.