Don't emit landing pads with -Z no-landing-pads

Closes #11647

src/librustc/middle/trans/base.rs

@@ -940,7 +940,7 @@ pub fn invoke<'a>(
         }
     }
 
-    if bcx.fcx.needs_invoke() {
+    if need_invoke(bcx) {
         unsafe {
             debug!("invoking {} at {}", llfn, bcx.llbb);
             for &llarg in llargs.iter() {

src/test/run-pass/no-landing-pads.rs

@@ -0,0 +1,32 @@
+// 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.
+
+// compile-flags: -Z no-landing-pads
+// xfail-fast
+
+use std::task;
+
+static mut HIT: bool = false;
+
+struct A;
+
+impl Drop for A {
+    fn drop(&mut self) {
+        unsafe { HIT = true; }
+    }
+}
+
+fn main() {
+    do task::try::<()> {
+        let _a = A;
+        fail!();
+    };
+    assert!(unsafe { !HIT });
+}