Added Objective-C @try block parsing.

src/shared/cplusplus/CheckExpression.cpp

@@ -305,6 +305,12 @@ bool CheckExpression::visit(ThrowExpressionAST *ast)
     return false;
 }
 
+bool CheckExpression::visit(ObjCThrowExpressionAST *ast)
+{
+    FullySpecifiedType exprTy = semantic()->check(ast->expression, _scope);
+    return false;
+}
+
 bool CheckExpression::visit(TypeIdAST *ast)
 {
     FullySpecifiedType typeSpecTy = semantic()->check(ast->type_specifier_list, _scope);