Add initialization info to MoveData

* Used for new dataflow to track if a variable has every been initialized
* Used for other dataflows that need to be updated for initializations

src/test/compile-fail/borrowck/borrowck-storage-dead.rs

@@ -16,6 +16,12 @@ fn ok() {
     }
 }
 
+fn also_ok() {
+    loop {
+        let _x = String::new();
+    }
+}
+
 fn fail() {
     loop {
         let x: i32;
@@ -26,5 +32,6 @@ fn fail() {
 
 fn main() {
     ok();
+    also_ok();
     fail();
 }

src/test/compile-fail/issue-45199.rs

@@ -0,0 +1,41 @@
+// Copyright 2012 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.
+
+// revisions: ast mir
+//[mir]compile-flags: -Zborrowck=mir
+
+fn test_drop_replace() {
+    let b: Box<isize>;
+    b = Box::new(1);    //[ast]~ NOTE first assignment
+                        //[mir]~^ NOTE first assignment
+    b = Box::new(2);    //[ast]~ ERROR cannot assign twice to immutable variable
+                        //[mir]~^ ERROR cannot assign twice to immutable variable `b`
+                        //[ast]~| NOTE cannot assign twice to immutable
+                        //[mir]~| NOTE cannot assign twice to immutable
+}
+
+fn test_call() {
+    let b = Box::new(1);    //[ast]~ NOTE first assignment
+                            //[mir]~^ NOTE first assignment
+    b = Box::new(2);        //[ast]~ ERROR cannot assign twice to immutable variable
+                            //[mir]~^ ERROR cannot assign twice to immutable variable `b`
+                            //[ast]~| NOTE cannot assign twice to immutable
+                            //[mir]~| NOTE cannot assign twice to immutable
+}
+
+fn test_args(b: Box<i32>) {  //[ast]~ NOTE first assignment
+                                //[mir]~^ NOTE first assignment
+    b = Box::new(2);            //[ast]~ ERROR cannot assign twice to immutable variable
+                                //[mir]~^ ERROR cannot assign twice to immutable variable `b`
+                                //[ast]~| NOTE cannot assign twice to immutable
+                                //[mir]~| NOTE cannot assign twice to immutable
+}
+
+fn main() {}