Makefile, true(1), false(1): ported true and false back to C for simplicity and size

Makefile

@@ -67,11 +67,11 @@ libgetopt: src/getopt-rs/lib.rs
 	$(RUSTC) $(RUSTCFLAGS) --crate-type=lib --crate-name=getopt \
 		-o build/o/libgetopt.rlib src/getopt-rs/lib.rs
 
-dj: src/dj.c build_dir
+dj: src/dj.c build
 	$(CC) $(CFLAGS) -o build/bin/dj src/dj.c
 
-false: src/false.rs build
-	$(RUSTC) $(RUSTFLAGS) -o build/bin/false src/false.rs
+false: src/false.c build
+	$(CC) $(CFLAGS) -o build/bin/false src/false.c
 
 fop: src/fop.rs build libgetopt sysexits
 	$(RUSTC) $(RUSTFLAGS) --extern getopt=build/o/libgetopt.rlib \
@@ -89,5 +89,5 @@ str: src/str.c build
 strcmp: src/strcmp.c build
 	$(CC) $(CFLAGS) -o build/bin/strcmp src/strcmp.c
 
-true: src/true.rs build
-	$(RUSTC) $(RUSTFLAGS) -o build/bin/true src/true.rs
+true: src/true.c build
+	$(CC) $(CFLAGS) -o build/bin/true src/true.c

src/false.c

@@ -1,5 +1,4 @@
 /*
- * Copyright (c) 2023 DTB <trinity@trinity.moe>
  * Copyright (c) 2023 Emma Tebibyte <emma@tebibyte.media>
  * SPDX-License-Identifier: CC0
  *
@@ -7,5 +6,4 @@
  * <http://creativecommons.org/publicdomain/zero/1.0>.
  */
 
-
-fn main() { }
+int main() { return 1; }

src/true.c

@@ -1,5 +1,4 @@
 /*
- * Copyright (c) 2023 DTB <trinity@trinity.moe>
  * Copyright (c) 2023 Emma Tebibyte <emma@tebibyte.media>
  * SPDX-License-Identifier: CC0
  *
@@ -7,8 +6,4 @@
  * <http://creativecommons.org/publicdomain/zero/1.0>.
  */
 
-use std::process::ExitCode;
-
-fn main() -> ExitCode {
-    ExitCode::from(1)
-}
+int main() {}