feat: add support for booleans and comparision operators

tests/booleans.c

@@ -0,0 +1,27 @@
+#include <stdbool.h>
+
+extern bool eq(int a, int b);
+extern bool neq(int a, int b);
+extern bool lt(int a, int b);
+extern bool lte(int a, int b);
+extern bool gt(int a, int b);
+extern bool gte(int a, int b);
+extern bool not_bool(bool a);
+
+int main() {
+    if (!eq(5, 5)) return 1;
+    if (eq(5, 6)) return 2;
+    if (!neq(5, 6)) return 3;
+    if (neq(5, 5)) return 4;
+    if (!lt(4, 5)) return 5;
+    if (lt(5, 5)) return 6;
+    if (!lte(5, 5)) return 7;
+    if (lte(6, 5)) return 8;
+    if (!gt(6, 5)) return 9;
+    if (gt(5, 5)) return 10;
+    if (!gte(5, 5)) return 11;
+    if (gte(4, 5)) return 12;
+    if (!not_bool(false)) return 13;
+    if (not_bool(true)) return 14;
+    return 0; // Success
+}

tests/booleans.src

@@ -0,0 +1,7 @@
+fn eq(a: i32, b: i32) -> bool { return a == b; }
+fn neq(a: i32, b: i32) -> bool { return a != b; }
+fn lt(a: i32, b: i32) -> bool { return a < b; }
+fn lte(a: i32, b: i32) -> bool { return a <= b; }
+fn gt(a: i32, b: i32) -> bool { return a > b; }
+fn gte(a: i32, b: i32) -> bool { return a >= b; }
+fn not_bool(a: bool) -> bool { return !a; }

tests/return_42.src

@@ -1,3 +1,3 @@
 fn main() -> i32 {
-    return 42;
+    return 10 * 4 + 2;
 }