two changes are made:
1. always enable flag_pic for fdpic. without this, various ICE and bad
codegen was observed.
2. allow sibcall for fdpic; it's valid since r12 is call-clobbered.
binutils-2.25.1/0003-shemuls.diff is needed to include the existing
fdpic support in the build when targeting sh*-linux-* rather than
tucking it away under sh*-uclinux-* only
gcc-5.2.0/0007-fdpic.diff is based on the original abandoned fdpic
patch 3/3 sent to the gcc list in 2010, updated for modern gcc and
with the uclinux dependencies removed. the original is here:
https://gcc.gnu.org/ml/gcc-patches/2010-08/msg01464.html
gcc-5.2.0/0001-musl.diff has been updated to use the right musl
dynamic linker pathname for fdpic so that musl-specific changes can be
avoided in the main fdpic patch.
at present, additional patches to musl are needed to produce working
binaries for the target.
Rich Felker