==== tests/cases/compiler/functionArgShadowing.ts (3 errors) ====
    class A { foo() { } }
    class B { bar() { } }
    function foo(x: A) {
       var x: B = new B();
           ~
!!! Subsequent variable declarations must have the same type.  Variable 'x' must be of type 'A', but here has type 'B'.
         x.bar(); // the property bar does not exist on a value of type A
           ~~~
!!! Property 'bar' does not exist on type 'A'.
    }
     
    class C {
    	constructor(public p: number) {
    		var p: string;
    		    ~
!!! Subsequent variable declarations must have the same type.  Variable 'p' must be of type 'number', but here has type 'string'.
    
    		var n: number = p;
    	}
    }