Add mblen.c to 64-bit libandroid-support build

packages/libandroid-support/build.sh

@@ -10,7 +10,8 @@ termux_step_post_extract_package () {
 	if [ "$TERMUX_ARCH_BITS" = "64" ]; then
 		# https://android.googlesource.com/platform/ndk.git/+/7c811775212f8ae0ecdcf60d05fefb1582207038
 		# For 64-bit bionic has almost everything except the following:
-		mkdir -p src/musl-locale/ include/
+		mkdir -p src/musl-locale/ src/musl-multibyte/ include/
+		cp $NDK/sources/android/support/src/musl-multibyte/mblen.c src/musl-multibyte/
 		cp $NDK/sources/android/support/src/musl-locale/{catclose.c,catgets.c,catopen.c} src/musl-locale/
 		cp $NDK/sources/android/support/include/* include/
 	else