Check bounds when looking up type parameters

A mismatched type with more type parameters than the expected one causes
`typeck` looking up out of the bound of type parameter vector, which
leads to ICE.

Closes #13466

src/test/compile-fail/issue-13466.rs

@@ -0,0 +1,22 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// Regression test for #13466
+
+pub fn main() {
+    // The expected arm type `Option<T>` has one type parameter, while
+    // the actual arm `Result<T, E>` has two. typeck should not be
+    // tricked into looking up a non-existing second type parameter.
+    let _x: uint = match Some(1u) {
+    //~^ ERROR mismatched types: expected `uint` but found `<generic #0>`
+        Ok(u) => u, //~ ERROR  mismatched types: expected `std::option::Option<uint>`
+        Err(e) => fail!(e)  //~ ERROR mismatched types: expected `std::option::Option<uint>`
+    };
+}