this adds support for riscv and fixes a bug in swab.h, allowing
to build newer kernels - the objtool component is built using
host kernel headers, not the ones available in-tree.
both 4.19.90 from official kernel tarball and 4.19.88 from the
sabotage-linux headers-only package are added. the latter should be
preferred unless you have a reason not to, as it's much smaller and
has some patches that improve interaction with musl.
support for all earlier kernel header versions will be dropped soon,
since everything prior to 4.16 has incompatibilities with 32-bit archs
moving to time64.
as maintained in https://github.com/sabotage-linux/kernel-headers .
downloading (and extracting) a 100+ MB kernel source tarball just for
the headers is extremely inefficient.
sabotage linux' kernel-headers tarball provides the same (including
musl compatibility fixes) in ~800 KB.
in order to use it, specify
LINUX_VER = headers-4.4.2-4
in your config.mak.
if LINUX_VER lacks the "headers-" prefix, the official source tarball
will be downloaded as usual.
new patch: 0017-c++-abi-break.diff fixes a C++ ABI break regression.
0010-static-pie-support.diff was removed as it doesn't apply anymore,
and forward-porting it requires arcane knowledge of GCC details.
the patches 0018 and 0019 have been copied from GCC 7.3.0. the static
pie patch from GCC 6.4.0, renumbered 0020, depends on the reversions
they make.
GCC 6.4.0 has one big advantage over 6.3.0: it is shipped as .tar.xz,
shaving 30 MB from its download size, and also considerably speeding
up the extraction process.
All patches are copies of the GCC 6.3.0 ones, except
0004-posix_memalign.diff which was rebased to apply cleanly.
0014-ubsan-empty-string-fix.diff was removed, since it was upstreamed.
