unix: build zlib with EXTRA_TARGET_CFLAGS

Author: indygreg

cpython-unix/build-zlib.sh

@@ -13,6 +13,6 @@ tar -xf zlib-${ZLIB_VERSION}.tar.gz
 
 pushd zlib-${ZLIB_VERSION}
 
-CFLAGS="-fPIC" ./configure --prefix=/tools/deps
+CFLAGS="${EXTRA_TARGET_CFLAGS} -fPIC" ./configure --prefix=/tools/deps
 make -j ${NUM_CPUS}
 make -j ${NUM_CPUS} install DESTDIR=${ROOT}/out