message: Allow override of cargo
diff: @@ -6,12 +6,14 @@ ifneq ($(TARGET),)
  CARGOFLAGS+="--target=$(TARGET)"
  endif
  +CARGO?=cargo
  +
  ifeq ($(TARGET),aarch64-unknown-linux-gnu)
  - CC=aarch64-linux-gnu-gcc
  + CC?=aarch64-linux-gnu-gcc
  endif
  ifeq ($(TARGET),x86_64-unknown-redox)
  - CC=x86_64-unknown-redox-gcc
  + CC?=x86_64-unknown-redox-gcc
  endif
  SRC=\
  @@ -26,11 +28,11 @@ SRC=\
  all: | libc libm
  clean:
  - cargo clean
  + $(CARGO) clean
  make -C tests clean
  check:
  - cargo check
  + $(CARGO) check
  fmt:
  ./fmt.sh
  @@ -64,27 +66,27 @@ test: sysroot
  make -C tests run
  $(BUILD)/debug/libc.a: $(SRC)
  - cargo build $(CARGOFLAGS)
  + $(CARGO) build $(CARGOFLAGS)
  touch $@
  $(BUILD)/debug/crt0.o: $(SRC)
  - CARGO_INCREMENTAL=0 cargo rustc --manifest-path src/crt0/Cargo.toml $(CARGOFLAGS) -- --emit obj=$@
  + CARGO_INCREMENTAL=0 $(CARGO) rustc --manifest-path src/crt0/Cargo.toml $(CARGOFLAGS) -- --emit obj=$@
  touch $@
  $(BUILD)/release/libc.a: $(SRC)
  - cargo build --release $(CARGOFLAGS)
  + $(CARGO) build --release $(CARGOFLAGS)
  touch $@
  $(BUILD)/release/crt0.o: $(SRC)
  - CARGO_INCREMENTAL=0 cargo rustc --release --manifest-path src/crt0/Cargo.toml $(CARGOFLAGS) -- --emit obj=$@
  + CARGO_INCREMENTAL=0 $(CARGO) rustc --release --manifest-path src/crt0/Cargo.toml $(CARGOFLAGS) -- --emit obj=$@
  touch $@
  $(BUILD)/release/crti.o: $(SRC)
  - CARGO_INCREMENTAL=0 cargo rustc --release --manifest-path src/crti/Cargo.toml $(CARGOFLAGS) -- --emit obj=$@
  + CARGO_INCREMENTAL=0 $(CARGO) rustc --release --manifest-path src/crti/Cargo.toml $(CARGOFLAGS) -- --emit obj=$@
  touch $@
  $(BUILD)/release/crtn.o: $(SRC)
  - CARGO_INCREMENTAL=0 cargo rustc --release --manifest-path src/crtn/Cargo.toml $(CARGOFLAGS) -- --emit obj=$@
  + CARGO_INCREMENTAL=0 $(CARGO) rustc --release --manifest-path src/crtn/Cargo.toml $(CARGOFLAGS) -- --emit obj=$@
  touch $@
  $(BUILD)/include: $(SRC)
  