Revert r307689

The proposed change ("Fix building of llvm's unwind if gcc has been
also built") breaks the build with clang/llvm.

Tested with...

	(
	export SRCCONF=/dev/null WITH_CLANG=
	cd gnu/lib/libgcc; make obj; make depend; make all
	)

MFC after:	3 days
X-MFC with:	r307689
Pointyhat to:	bapt
Reported by:	Jenkins, O. Hartmann <ohartman@zedat.fu-berlin.de>
Sponsored by:	Dell EMC Isilon

gnu/lib/libgcc/Makefile

@@ -30,7 +30,8 @@ CFLAGS+=	-DTARGET_ARM_EABI
 CFLAGS+=	-DIN_GCC -DIN_LIBGCC2 -D__GCC_FLOAT_NOT_NEEDED \
 		-DHAVE_GTHR_DEFAULT \
 		-I${GCCLIB}/include \
-		-I${GCCDIR}/config -I${GCCDIR} -I.
+		-I${GCCDIR}/config -I${GCCDIR} -I. \
+		-I${CCDIR}/cc_tools
 
 LDFLAGS+=	-nodefaultlibs
 LIBADD+=	c
@@ -101,12 +102,6 @@ CFLAGS+=	-I${SRCTOP}/contrib/libc++/include
 
 .else # MK_LLVM_LIBUNWIND
 
-#
-# Prevent the potential unwind.h from gcc (generated)
-# to be in the include path before the one from llvm unwind
-#
-CFLAGS+=	-I${CCDIR}/cc_tools
-
 .if ${TARGET_CPUARCH} == "arm"
 LIB2ADDEH =	unwind-arm.c libunwind-arm.S pr-support.c unwind-c.c
 .else