Merge tag 'kbuild-fixes-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git...

Merge tag 'kbuild-fixes-v4.19-2' of git://git./linux/kernel/git/masahiroy/linux-kbuild

Masahiro writes:
  "Kbuild fixes for v4.19 (2nd)
   - Fix warnings from recordmcount.pl when building with Clang
   - Allow Clang to use GNU toolchains correctly
   - Disable CONFIG_SAMPLES for UML to avoid build error"

* tag 'kbuild-fixes-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  samples: disable CONFIG_SAMPLES for UML
  kbuild: allow to use GCC toolchain not in Clang search path
  ftrace: Build with CPPFLAGS to get -Qunused-arguments