feat: add floats

tests/float_f32_arithmetic.test

@@ -0,0 +1,20 @@
+[code]
+fn test_f32(x: f32, y: f32) -> f32 {
+    let z: f32 = 1.5;
+    // (4.0 + 2.0) * 1.5 - (4.0 / 2.0) = 6.0 * 1.5 - 2.0 = 9.0 - 2.0 = 7.0
+    return (x + y) * z - (x / y);
+}
+
+[harness]
+extern float test_f32(float x, float y);
+
+int main() {
+    float result = test_f32(4.0f, 2.0f);
+    if (result == 7.0f) {
+        return 0;
+    }
+    return 1;
+}
+
+[expected_return_code]
+0