[analyzer] Small SMT API improvement

[esteffin]

Summary

Removed const qualifier from reset method of SMTSolver and Z3Solver objects.

[NoQ]

Fair enough :)

include/clang/StaticAnalyzer/Core/PathSensitive/SMTSolver.h

public:
 
   /// Push the current solver state
   virtual void push() = 0;
 
   /// Pop the previous solver state
   virtual void pop(unsigned NumStates = 1) = 0;
 
   /// Reset the solver and remove all constraints.
-  virtual void reset() const = 0;
+  virtual void reset() = 0;
 
   virtual void print(raw_ostream &OS) const = 0;
 };
 
 /// Shared pointer for SMTSolvers.
 using SMTSolverRef = std::shared_ptr<SMTSolver>;
 
 /// Convenience method to create and Z3Solver object
 SMTSolverRef CreateZ3Solver();
 
 } // namespace ento
 } // namespace clang
 
 #endif

lib/StaticAnalyzer/Core/Z3ConstraintManager.cpp

public:
 
   /// Get a model from the solver. Caller should check the model is
   /// satisfiable.
   Z3Model getModel() {
     return Z3Model(Context, Z3_solver_get_model(Context.Context, Solver));
   }
 
   /// Reset the solver and remove all constraints.
-  void reset() const override { Z3_solver_reset(Context.Context, Solver); }
+  void reset() override { Z3_solver_reset(Context.Context, Solver); }
 
   void print(raw_ostream &OS) const override {
     OS << Z3_solver_to_string(Context.Context, Solver);
   }
 }; // end class Z3Solver
 
 class Z3ConstraintManager : public SMTConstraintManager<ConstraintZ3, Z3Expr> {
   SMTSolverRef Solver = CreateZ3Solver();