feat: impl Default for Solver, Optimize, and Parser (#456)

Appeasing clippy in rust 1.90

Author: toolCHAINZ

z3/src/optimize.rs

@@ -283,6 +283,12 @@ impl Optimize {
     }
 }
 
+impl Default for Optimize {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl fmt::Display for Optimize {
     fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
         let p = unsafe { Z3_optimize_to_string(self.ctx.z3_ctx.0, self.z3_opt) };

z3/src/params.rs

@@ -65,6 +65,12 @@ impl Params {
     }
 }
 
+impl Default for Params {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 /// Get a global (or module) parameter.
 ///
 /// # See also

z3/src/solver.rs

@@ -557,6 +557,12 @@ impl Solver {
     }
 }
 
+impl Default for Solver {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 struct SolverIterator<T> {
     solver: Solver,
     ast: T,