Hi Greg and Sasha,
Please consider applying the following patches to 6.4 and 6.3, they should apply cleanly.
08f6554ff90e ("mips: Include KBUILD_CPPFLAGS in CHECKFLAGS invocation") a7e5eb53bf9b ("powerpc/vdso: Include CLANG_FLAGS explicitly in ldflags-y") cff6e7f50bd3 ("kbuild: Add CLANG_FLAGS to as-instr") 43fc0a99906e ("kbuild: Add KBUILD_CPPFLAGS to as-option invocation") feb843a469fb ("kbuild: add $(CLANG_FLAGS) to KBUILD_CPPFLAGS")
They resolve and help avoid build breakage with tip of tree clang, which has become a little stricter in the flags that it will accept for a particular target, which requires '--target=' to be passed along to all invocations of $(CC). Our continuous integration does not currently show any breakage with 6.1 and earlier; should these patches be needed there, I will send them at a later time.
Cheers, Nathan