test(overload): add negative tests for overload

unittest/negative/overload_error1.decaf

+class A
+{
+	void print ()
+	{
+		Print ( "A.print\n" );
+	}
+}
+
+class B extends A
+{
+	void print ()
+	{
+		Print ( "B.print\n" );
+	}
+}
+
+class F
+{
+	static void f ( class A a, class A b )
+	{
+		Print ( "F: A A\n" );
+		a.print ();
+		b.print ();
+	}
+}
+
+class G
+{
+	static void f ( class A a, class A b )
+	{
+		Print ( "G: A A\n" );
+	}
+
+	static void f ( class A a, class B b )
+	{
+		Print ( "G: A B\n" );
+	}
+
+	static void f ( class B a, class A b )
+	{
+		Print ( "G: B A\n" );
+	}
+
+	static void f ( string s )
+	{
+		Print ( "G: string\n" );
+	}
+}
+
+class Main
+{
+	static void main ()
+	{
+		class A a;
+		a = new A ();
+		class B b;
+		b = new B ();
+
+		F.f ( a, a );
+		F.f ( a, b );
+		F.f ( b, a );
+		F.f ( b, b );
+		F.f ( 1 );
+
+		G.f ( a, a );
+		G.f ( a, b );
+		G.f ( b, a );
+		G.f ( b, b );
+		G.f ( 1 );
+	}
+}
\ No newline at end of file

unittest/negative/override_error1.decaf

+class A
+{
+	void print ()
+	{
+		Print ( "A.print\n" );
+	}
+}
+
+class B extends A
+{
+	void print ()
+	{
+		Print ( "B.print\n" );
+	}
+}
+
+class F
+{
+	void f ( class A a )
+	{
+
+	}
+
+	void f ( class B b )
+	{
+
+	}
+
+	int g;
+
+	string h;
+}
+
+class G extends F
+{
+	int f;
+
+	void g ( class A a )
+	{
+
+	}
+
+	void g ( class B b )
+	{
+
+	}
+
+	bool h;
+}
+
+class Main
+{
+	static void main ()
+	{
+	}
+}
\ No newline at end of file

unittest/negative/redef_error1.decaf

+class A
+{
+	void print ()
+	{
+		Print ( "A.print\n" );
+	}
+}
+
+class B extends A
+{
+	void print ()
+	{
+		Print ( "B.print\n" );
+	}
+}
+
+class F
+{
+	void f ( class A a )
+	{
+
+	}
+
+	int f ( class A c )
+	{
+
+	}
+
+	class A f ( class A abc )
+	{
+
+	}
+
+	void f ( class A b )
+	{
+
+	}
+
+	int g;
+
+	string h;
+}
+
+class Main
+{
+	static int main ( int a, int b )
+	{
+
+	}
+
+	static void main ()
+	{
+	}
+
+	static int main ( int c, int d )
+	{
+
+	}
+
+	static int main ()
+	{
+
+	}
+
+	static void main ( int a )
+	{
+		
+	}
+}
\ No newline at end of file

unittest/negative/result/overload_error1.result

+*** Error at (63,5): function 'f' expects 2 argument(s) but 1 given
+*** Error at (68,5): call of overloaded f(class : B, class : B) is ambiguous, candidates are :
+        *** note  : candidate at (34,14) : void f(class : A, class : B)
+        *** note  : candidate at (39,14) : void f(class : B, class : A)
+*** Error at (69,5): no match function for call to f(int), candidates are :
+        *** note  : candidate at (29,14) : void f(class : A, class : A)
+            error : function 'f' expects 2 argument(s) but 1 given
+        *** note  : candidate at (34,14) : void f(class : A, class : B)
+            error : function 'f' expects 2 argument(s) but 1 given
+        *** note  : candidate at (39,14) : void f(class : B, class : A)
+            error : function 'f' expects 2 argument(s) but 1 given
+        *** note  : candidate at (44,14) : void f(string)
+            error : incompatible argument 1: int given, string expected

unittest/negative/result/override_error1.result

+*** Error at (36,6): declaration of 'f' here conflicts with earlier declarations : 
+        *** note  : previously declared at (19,7) : void f(class : A)
+        *** note  : previously declared at (24,7) : void f(class : B)
+*** Error at (38,7): declaration of 'g' here conflicts with earlier declaration at (29,6)
+*** Error at (43,7): declaration of 'g' here conflicts with earlier declaration at (29,6)
+*** Error at (48,7): overriding variable is not allowed for var 'h'

unittest/negative/result/redef_error1.result

+*** Error at (24,6): ambiguous new declaration of 'int f(class : A)' :
+        *** note  : previous declaration at (19,7) : void f(class : A)
+*** Error at (29,10): ambiguous new declaration of 'class : A f(class : A)' :
+        *** note  : previous declaration at (19,7) : void f(class : A)
+*** Error at (34,7): redefinition of 'void f(class : A)' :
+        *** note  : previous declaration at (19,7) : void f(class : A)
+*** Error at (51,14): conflicting declaration of main function 'void main()' :
+        *** note  : previous declaration at (46,13) : int main(int, int)
+*** Error at (55,13): redefinition of 'int main(int, int)' :
+        *** note  : previous declaration at (46,13) : int main(int, int)
+*** Error at (60,13): ambiguous new declaration of 'int main()' :
+        *** note  : previous declaration at (51,14) : void main()
+*** Error at (65,14): conflicting declaration of main function 'void main(int)' :
+        *** note  : previous declaration at (46,13) : int main(int, int)
+        *** note  : previous declaration at (51,14) : void main()