kbuild: fix cc1 options check to ensure we do not use -fPIC when compiling

The arch/*/boot/Makefile use cc-options to check for GCC command options
and cc-options use the hardened specs when checking for GCC command
options.  When -fPIE is pass to cc1 it can't use -ffreestanding or
-fno-toplevel-reorder.  Then it fail to build stuff with -ffreestanding
and -fno-toplevel-reorder.

Thanks to Fredric Johansson for finding the main problem behind a failed
build using a hardened toolchain.
Signed-off-by: Magnus Granberg <zorry@ume.nu>
Signed-off-by: Jory A. Pratt <anarchy@gentoo.org>
Cc: Fredric Johansson <johansson_fredric@hotmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

scripts/Kbuild.include

@@ -106,12 +106,12 @@ as-instr = $(call try-run,\
 # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586)
 
 cc-option = $(call try-run,\
-	$(CC) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",$(1),$(2))
+	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",$(1),$(2))
 
 # cc-option-yn
 # Usage: flag := $(call cc-option-yn,-march=winchip-c6)
 cc-option-yn = $(call try-run,\
-	$(CC) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",y,n)
+	$(CC) $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(1) -c -xc /dev/null -o "$$TMP",y,n)
 
 # cc-option-align
 # Prefix align with either -falign or -malign