message: Fix ar usage in Makefile for macOS compatibility
diff: @@ -13,16 +13,19 @@ endif
  ifeq ($(TARGET),aarch64-unknown-linux-gnu)
  export CC=aarch64-linux-gnu-gcc
  export LD=aarch64-linux-gnu-ld
  + export AR=aarch64-linux-gnu-ar
  endif
  ifeq ($(TARGET),aarch64-unknown-redox)
  export CC=aarch64-unknown-redox-gcc
  export LD=aarch64-unknown-redox-ld
  + export AR=aarch64-unknown-redox-ar
  endif
  ifeq ($(TARGET),x86_64-unknown-redox)
  export CC=x86_64-unknown-redox-gcc
  export LD=x86_64-unknown-redox-ld
  + export AR=x86_64-unknown-redox-ar
  endif
  SRC=\
  @@ -96,7 +99,7 @@ $(BUILD)/debug/libc.a: $(BUILD)/debug/librelibc.a $(BUILD)/pthreads-emb/libpthre
  done
  echo "save" >> "$@.mri"
  echo "end" >> "$@.mri"
  - ar -M < "$@.mri"
  + $(AR) -M < "$@.mri"
  $(BUILD)/debug/libc.so: $(BUILD)/debug/librelibc.a $(BUILD)/pthreads-emb/libpthread.a $(BUILD)/openlibm/libopenlibm.a
  $(CC) -nostdlib -shared -Wl,--allow-multiple-definition -Wl,--whole-archive $^ -Wl,--no-whole-archive -o $@
  @@ -133,7 +136,7 @@ $(BUILD)/release/libc.a: $(BUILD)/release/librelibc.a $(BUILD)/pthreads-emb/libp
  done
  echo "save" >> "$@.mri"
  echo "end" >> "$@.mri"
  - ar -M < "$@.mri"
  + $(AR) -M < "$@.mri"
  $(BUILD)/release/libc.so: $(BUILD)/release/librelibc.a $(BUILD)/pthreads-emb/libpthread.a $(BUILD)/openlibm/libopenlibm.a
  $(CC) -nostdlib -shared -Wl,--allow-multiple-definition -Wl,--whole-archive $^ -Wl,--no-whole-archive -o $@
  