Add compile-fail tests for unsound moving out of enums (#2329)

Author: bblum

src/test/compile-fail/bind-by-move-neither-can-live-while-the-other-survives-1.rs

@@ -0,0 +1,9 @@
+struct X { x: (); drop { error!("destructor runs"); } }
+
+fn main() {
+    let x = some(X { x: () });
+    match move x {
+        some(ref _y @ move _z) => { }, //~ ERROR cannot bind by-move and by-ref in the same pattern
+        none => fail
+    }
+}

src/test/compile-fail/bind-by-move-neither-can-live-while-the-other-survives-2.rs

@@ -0,0 +1,9 @@
+struct X { x: (); drop { error!("destructor runs"); } }
+
+fn main() {
+    let x = some((X { x: () }, X { x: () }));
+    match move x {
+        some((ref _y, move _z)) => { }, //~ ERROR cannot bind by-move and by-ref in the same pattern
+        none => fail
+    }
+}

src/test/compile-fail/bind-by-move-neither-can-live-while-the-other-survives-3.rs

@@ -0,0 +1,11 @@
+struct X { x: (); drop { error!("destructor runs"); } }
+
+enum double_option<T,U> { some2(T,U), none2 }
+
+fn main() {
+    let x = some2(X { x: () }, X { x: () });
+    match move x {
+        some2(ref _y, move _z) => { }, //~ ERROR cannot bind by-move and by-ref in the same pattern
+        none2 => fail
+    }
+}

src/test/compile-fail/bind-by-move-no-guards.rs

@@ -0,0 +1,10 @@
+fn main() {
+    let (c,p) = pipes::stream();
+    let x = some(p);
+    c.send(false);
+    match move x {
+        some(move z) if z.recv() => { fail }, //~ ERROR cannot bind by-move into a pattern guard
+        some(move z) => { assert !z.recv(); },
+        none => fail
+    }
+}

src/test/compile-fail/bind-by-move-no-lvalues-1.rs

@@ -0,0 +1,9 @@
+struct X { x: (); drop { error!("destructor runs"); } }
+
+fn main() {
+    let x = some(X { x: () });
+    match x {
+        some(move _z) => { }, //~ ERROR cannot bind by-move when matching an lvalue
+        none => fail
+    }
+}

src/test/compile-fail/bind-by-move-no-lvalues-2.rs

@@ -0,0 +1,10 @@
+struct X { x: (); drop { error!("destructor runs"); } }
+struct Y { y: option<X>; }
+
+fn main() {
+    let x = Y { y: some(X { x: () }) };
+    match x.y {
+        some(move _z) => { }, //~ ERROR cannot bind by-move when matching an lvalue
+        none => fail
+    }
+}

src/test/compile-fail/bind-by-move-no-sub-bindings.rs

@@ -0,0 +1,9 @@
+struct X { x: (); drop { error!("destructor runs"); } }
+
+fn main() {
+    let x = some(X { x: () });
+    match move x {
+        some(move _y @ ref _z) => { }, //~ ERROR cannot bind by-move with sub-bindings
+        none => fail
+    }
+}