gcc: version update to 8.3.0, macOS Mojave compliant

gnugcc/Makefile

@@ -10,7 +10,21 @@ gnugcc_clone:
 	if [ ! -d "gcc-$(GCC_VERSION)" ]; then tar xzf gcc-$(GCC_VERSION).tar.gz; fi
 
 gnugcc_config:
-	( cd gcc-$(GCC_VERSION); CFLAGS="" CXXFLAGS="" ./configure --prefix=${BSPTOOLS} --enable-checking=release --with-gmp=${BSPTOOLS} --with-mpfr=${BSPTOOLS} --with-mpc=${BSPTOOLS} --enable-languages=c,c++ --with-isl=${BSPTOOLS} --program-suffix=-$(GCC_VERSION); )
+	( cd gcc-$(GCC_VERSION); \
+		CFLAGS="" CXXFLAGS="" \
+		./configure --prefix=${BSPTOOLS} \
+		--with-gmp=${BSPTOOLS} \
+		--with-mpfr=${BSPTOOLS} \
+		--with-mpc=${BSPTOOLS} \
+		--with-isl=${BSPTOOLS} \
+		--enable-checking=release \
+		--enable-languages=c,c++ \
+		--disable-multilib \
+		--disable-nls \
+		--with-sysroot=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk \
+		--with-native-system-header-dir=/usr/include \
+		--program-suffix=-$(GCC_VERSION); \
+	)
 
 gnugcc_build:
 	make -C gcc-$(GCC_VERSION) -j ${BSPJOB}