Hi Greg and Sasha,

Please find attached backports for commit feb843a469fb ("kbuild: add
$(CLANG_FLAGS) to KBUILD_CPPFLAGS") and its dependent changes, commit
d5c8d6e0fa61 ("kbuild: Update assembler calls to use proper flags and
language target") and its dependent changes, and commit 7db038d9790e
("drm/amd/display: Do not add '-mhard-float' to dml_ccflags for clang")
for 6.1 and earlier. The second listed change is already in 6.1 so that
series is a little shorter.

These changes are needed there due to an upstream LLVM change [1] that
changes the behavior of -Qunused-arguments with unknown target options,
which is only used in 6.1 and older since I removed it in commit
8d9acfce3332 ("kbuild: Stop using '-Qunused-arguments' with clang") in
6.3.

Please let me know if there are any issues, I will try to pay attention
for any issues that crop up in the stable review period from these
changes but please ping me if you remember.

Cheers,
Nathan

[1]: https://github.com/llvm/llvm-project/commit/a4b2f4a72aa9b4655ecc723838830e0a7f29c9ca