UPSTREAM: kbuild: clang: add -no-integrated-as to KBUILD_[AC]FLAGS

The Linux Kernel relies on GCC's acceptance of inline assembly as an
opaque object which will not have any validation performed on the content.
The current behaviour in LLVM is to perform validation of the contents by
means of parsing the input if the MC layer can handle it.

Disable clangs integrated assembler and use the GNU assembler instead.

Wording-mostly-from: Saleem Abdulrasool <[email protected]>
Signed-off-by: Michael Davidson <[email protected]>
Signed-off-by: Matthias Kaehlcke <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>
(cherry picked from commit a37c45cd82e62a361706b9688a984a3a63957321)

Makefile

@@ -720,6 +720,8 @@ KBUILD_CFLAGS += $(call cc-disable-warning, tautological-compare)
 # See modpost pattern 2
 KBUILD_CFLAGS += $(call cc-option, -mno-global-merge,)
 KBUILD_CFLAGS += $(call cc-option, -fcatch-undefined-behavior)
+KBUILD_CFLAGS += $(call cc-option, -no-integrated-as)
+KBUILD_AFLAGS += $(call cc-option, -no-integrated-as)
 else
 
 # These warnings generated too much noise in a regular build.