[PATCH] arch/x86: Propagate $(CLANG_FLAGS) to $(REALMODE_FLAGS)

[John Millikin]

When compiling with Clang, the `$(CLANG_FLAGS)' variable contains
additional flags needed to cross-compile C and Assembly sources:

* `-no-integrated-as' tells clang to assemble with GNU Assembler
  instead of its built-in LLVM assembler. This flag is set by default
  unless `LLVM_IAS=1' is set, because the LLVM assembler can't yet
  parse certain GNU extensions.

* `--target' sets the target architecture when cross-compiling. This
  flag must be set for both compilation and assembly (`KBUILD_AFLAGS')
  to support architecture-specific assembler directives.

Signed-off-by: John Millikin <john@xxxxxxxxxxxxxxxxx>
---
 arch/x86/Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/Makefile b/arch/x86/Makefile
index 7116da3980be..725c65532482 100644
--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -33,6 +33,11 @@ REALMODE_CFLAGS += -ffreestanding
 REALMODE_CFLAGS += -fno-stack-protector
 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), -Wno-address-of-packed-member)
 REALMODE_CFLAGS += $(call __cc-option, $(CC), $(REALMODE_CFLAGS), $(cc_stack_align4))
+
+ifdef CONFIG_CC_IS_CLANG
+REALMODE_CFLAGS += $(CLANG_FLAGS)
+endif
+
 export REALMODE_CFLAGS
 
 # BITS is used as extension for files which are available in a 32 bit
-- 
2.29.2