clang versions prior to the current development version of 13.0.0 cannot
compile s390 after commit 3abbdfde5a65 ("s390/bitops: use register pair
instead of register asm") and the s390 maintainers do not intend to work
around this in the kernel. Codify this in scripts/min-tool-version.sh
similar to arm64 with GCC 5.1.0 so that there are no reports of broken
builds.

[hca@linux.ibm.com: breaking compatibility with older clang compilers
 is intended to finally make use of a feature which allows the
 compiler to allocate even/odd register pairs. This is possible since
 a very long time with gcc, but only since llvm-project commit
 d058262b1471 ("[SystemZ] Support i128 inline asm operands.") with
 clang. Using that feature allows to get rid of error prone register
 asm statements, of which the above named kernel commit is only the
 first of a larger not yet complete series.]

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210617193139.856957-1-nathan@kernel.org


Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>