Add testing to build system

Generate a testing executable, and provide a recipe for running it.

Makefile

@@ -2,6 +2,7 @@ CC=cc
 
 DIST=build
 OUT=$(DIST)/alisp.out
+TEST=$(DIST)/test.out
 
 LDFLAGS=
 GFLAGS=-Wall -Wextra -Wpedantic -std=c23 -I./include/
@@ -16,21 +17,30 @@ CFLAGS=$(GFLAGS) $(DFLAGS)
 endif
 
 # Units to compile
-UNITS=src/main.c src/sv.c src/vec.c src/stream.c src/symtable.c src/tag.c src/lisp.c src/reader.c
+UNITS=src/sv.c src/vec.c src/stream.c src/symtable.c src/tag.c src/lisp.c
 OBJECTS:=$(patsubst src/%.c, $(DIST)/%.o, $(UNITS))
 
 # Dependency generation
 DEPFLAGS=-MT $@ -MMD -MP -MF
 DEPDIR=$(DIST)/deps
 
-$(OUT): $(OBJECTS) | $(DIST)
+all: $(OUT) $(TEST)
+
+$(OUT): $(OBJECTS) $(DIST)/main.o | $(DIST)
+	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
+
+$(TEST): $(OBJECTS) $(DIST)/test/test.o | $(DIST)
 	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)
 
 $(DIST)/%.o: src/%.c | $(DIST) $(DEPDIR)
 	$(CC) $(CFLAGS) $(DEPFLAGS) $(DEPDIR)/$*.d -c -o $@ $<
 
+$(DIST)/test/%.o: test/%.c | $(DIST) $(DEPDIR)
+	$(CC) $(CFLAGS) $(DEPFLAGS) $(DEPDIR)/$*.d -c -o $@ $<
+
 $(DIST):
 	mkdir -p $(DIST)
+	mkdir -p $(DIST)/test
 
 $(DEPDIR):
 	mkdir -p $(DEPDIR)
@@ -39,13 +49,16 @@ clangd: compile_commands.json
 compile_commands.json: Makefile
 	bear -- $(MAKE) -B MODE=debug
 
-.PHONY: run clean examples
+.PHONY: run test clean examples
 ARGS=
 run: $(OUT)
 	./$^ $(ARGS)
 
+test: $(TEST)
+	./$^
+
 clean:
 	rm -rf $(DIST)
 
-DEPS:=$(patsubst src/%.c,$(DEPDIR)/%.d, $(UNITS))
+DEPS:=$(patsubst src/%.c,$(DEPDIR)/%.d, $(UNITS)) $(DEPDIR)/main.d $(DEPDIR)/test.d
 include $(wildcard $(DEPS))