drivers/firmware/efi/libstub using $(CROSS_COMPILE){objcopy|strip}

[nickdesaulniers]

via: https://travis-ci.com/github/ClangBuiltLinux/continuous-integration/jobs/311246218

aarch64-linux-gnu-strip: warning: drivers/firmware/efi/libstub/lib-ctype.o: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0000000
aarch64-linux-gnu-objcopy: warning: drivers/firmware/efi/libstub/lib-ctype.o: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0000000

these builds should be using OBJCOPY=llvm-objcopy STRIP=llvm-strip.

[nickdesaulniers]

nevermind, we don't have objcopy/strip enabled...

[nickdesaulniers]

ClangBuiltLinux/continuous-integration#212