add hint to fix error for immutable ref in arg

src/test/ui/span/borrowck-borrow-overloaded-auto-deref-mut.stderr

@@ -0,0 +1,86 @@
+error: cannot borrow immutable argument `x` as mutable
+  --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:63:24
+   |
+62 | fn deref_mut_field1(x: Own<Point>) {
+   |                     - use `mut x` here to make mutable
+63 |     let __isize = &mut x.y; //~ ERROR cannot borrow
+   |                        ^ cannot borrow mutably
+
+error: cannot borrow immutable borrowed content `*x` as mutable
+  --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:75:10
+   |
+74 | fn deref_extend_mut_field1(x: &Own<Point>) -> &mut isize {
+   |                               ----------- use `&mut Own<Point>` here to make mutable
+75 |     &mut x.y //~ ERROR cannot borrow
+   |          ^
+
+error[E0499]: cannot borrow `*x` as mutable more than once at a time
+  --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:88:19
+   |
+87 |     let _x = &mut x.x;
+   |                   - first mutable borrow occurs here
+88 |     let _y = &mut x.y; //~ ERROR cannot borrow
+   |                   ^ second mutable borrow occurs here
+89 | }
+   | - first borrow ends here
+
+error: cannot borrow immutable argument `x` as mutable
+  --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:98:5
+   |
+97 | fn assign_field1<'a>(x: Own<Point>) {
+   |                      - use `mut x` here to make mutable
+98 |     x.y = 3; //~ ERROR cannot borrow
+   |     ^ cannot borrow mutably
+
+error: cannot borrow immutable borrowed content `*x` as mutable
+   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:102:5
+    |
+101 | fn assign_field2<'a>(x: &'a Own<Point>) {
+    |                         -------------- use `&'a mut Own<Point>` here to make mutable
+102 |     x.y = 3; //~ ERROR cannot borrow
+    |     ^
+
+error[E0499]: cannot borrow `*x` as mutable more than once at a time
+   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:111:5
+    |
+110 |     let _p: &mut Point = &mut **x;
+    |                                -- first mutable borrow occurs here
+111 |     x.y = 3; //~ ERROR cannot borrow
+    |     ^ second mutable borrow occurs here
+112 | }
+    | - first borrow ends here
+
+error: cannot borrow immutable argument `x` as mutable
+   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:119:5
+    |
+118 | fn deref_mut_method1(x: Own<Point>) {
+    |                      - use `mut x` here to make mutable
+119 |     x.set(0, 0); //~ ERROR cannot borrow
+    |     ^ cannot borrow mutably
+
+error: cannot borrow immutable borrowed content `*x` as mutable
+   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:131:5
+    |
+130 | fn deref_extend_mut_method1(x: &Own<Point>) -> &mut isize {
+    |                                ----------- use `&mut Own<Point>` here to make mutable
+131 |     x.y_mut() //~ ERROR cannot borrow
+    |     ^
+
+error: cannot borrow immutable argument `x` as mutable
+   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:139:6
+    |
+138 | fn assign_method1<'a>(x: Own<Point>) {
+    |                       - use `mut x` here to make mutable
+139 |     *x.y_mut() = 3; //~ ERROR cannot borrow
+    |      ^ cannot borrow mutably
+
+error: cannot borrow immutable borrowed content `*x` as mutable
+   --> $DIR/borrowck-borrow-overloaded-auto-deref-mut.rs:143:6
+    |
+142 | fn assign_method2<'a>(x: &'a Own<Point>) {
+    |                          -------------- use `&'a mut Own<Point>` here to make mutable
+143 |     *x.y_mut() = 3; //~ ERROR cannot borrow
+    |      ^
+
+error: aborting due to 10 previous errors
+

src/test/ui/span/borrowck-borrow-overloaded-deref-mut.stderr

@@ -0,0 +1,34 @@
+error: cannot borrow immutable argument `x` as mutable
+  --> $DIR/borrowck-borrow-overloaded-deref-mut.rs:39:25
+   |
+38 | fn deref_mut1(x: Own<isize>) {
+   |               - use `mut x` here to make mutable
+39 |     let __isize = &mut *x; //~ ERROR cannot borrow
+   |                         ^ cannot borrow mutably
+
+error: cannot borrow immutable borrowed content `*x` as mutable
+  --> $DIR/borrowck-borrow-overloaded-deref-mut.rs:51:11
+   |
+50 | fn deref_extend_mut1<'a>(x: &'a Own<isize>) -> &'a mut isize {
+   |                             -------------- use `&'a mut Own<isize>` here to make mutable
+51 |     &mut **x //~ ERROR cannot borrow
+   |           ^^
+
+error: cannot borrow immutable argument `x` as mutable
+  --> $DIR/borrowck-borrow-overloaded-deref-mut.rs:59:6
+   |
+58 | fn assign1<'a>(x: Own<isize>) {
+   |                - use `mut x` here to make mutable
+59 |     *x = 3; //~ ERROR cannot borrow
+   |      ^ cannot borrow mutably
+
+error: cannot borrow immutable borrowed content `*x` as mutable
+  --> $DIR/borrowck-borrow-overloaded-deref-mut.rs:63:6
+   |
+62 | fn assign2<'a>(x: &'a Own<isize>) {
+   |                   -------------- use `&'a mut Own<isize>` here to make mutable
+63 |     **x = 3; //~ ERROR cannot borrow
+   |      ^^
+
+error: aborting due to 4 previous errors
+

src/test/ui/span/borrowck-call-is-borrow-issue-12224.stderr

@@ -0,0 +1,43 @@
+error[E0499]: cannot borrow `f` as mutable more than once at a time
+  --> $DIR/borrowck-call-is-borrow-issue-12224.rs:23:16
+   |
+23 |     f(Box::new(|| {
+   |     -          ^^ second mutable borrow occurs here
+   |     |
+   |     first mutable borrow occurs here
+24 |     //~^ ERROR: cannot borrow `f` as mutable more than once
+25 |         f((Box::new(|| {})))
+   |         - borrow occurs due to use of `f` in closure
+26 |     }));
+   |       - first borrow ends here
+
+error: cannot borrow immutable borrowed content `*f` as mutable
+  --> $DIR/borrowck-call-is-borrow-issue-12224.rs:36:5
+   |
+35 | fn test2<F>(f: &F) where F: FnMut() {
+   |                -- use `&mut F` here to make mutable
+36 |     (*f)(); //~ ERROR: cannot borrow immutable borrowed content `*f` as mutable
+   |     ^^^^
+
+error: cannot borrow immutable `Box` content `*f.f` as mutable
+  --> $DIR/borrowck-call-is-borrow-issue-12224.rs:44:5
+   |
+44 |     f.f.call_mut(()) //~ ERROR: cannot borrow immutable `Box` content `*f.f` as mutable
+   |     ^^^
+
+error[E0504]: cannot move `f` into closure because it is borrowed
+  --> $DIR/borrowck-call-is-borrow-issue-12224.rs:63:13
+   |
+62 |     f(Box::new(|a| {
+   |     - borrow of `f` occurs here
+63 |         foo(f);
+   |             ^ move into closure occurs here
+
+error[E0507]: cannot move out of captured outer variable in an `FnMut` closure
+  --> $DIR/borrowck-call-is-borrow-issue-12224.rs:63:13
+   |
+63 |         foo(f);
+   |             ^ cannot move out of captured outer variable in an `FnMut` closure
+
+error: aborting due to 5 previous errors
+

src/test/ui/span/borrowck-call-method-from-mut-aliasable.stderr

@@ -0,0 +1,11 @@
+error: cannot borrow immutable borrowed content `*x` as mutable
+  --> $DIR/borrowck-call-method-from-mut-aliasable.rs:27:5
+   |
+25 | fn b(x: &Foo) {
+   |         ---- use `&mut Foo` here to make mutable
+26 |     x.f();
+27 |     x.h(); //~ ERROR cannot borrow
+   |     ^
+
+error: aborting due to previous error
+

src/test/ui/span/borrowck-fn-in-const-b.stderr

@@ -0,0 +1,10 @@
+error: cannot borrow immutable borrowed content `*x` as mutable
+  --> $DIR/borrowck-fn-in-const-b.rs:17:9
+   |
+16 |     fn broken(x: &Vec<String>) {
+   |                  ------------ use `&mut Vec<String>` here to make mutable
+17 |         x.push(format!("this is broken"));
+   |         ^
+
+error: aborting due to previous error
+

src/test/ui/span/borrowck-object-mutability.stderr

@@ -0,0 +1,17 @@
+error: cannot borrow immutable borrowed content `*x` as mutable
+  --> $DIR/borrowck-object-mutability.rs:19:5
+   |
+17 | fn borrowed_receiver(x: &Foo) {
+   |                         ---- use `&mut Foo` here to make mutable
+18 |     x.borrowed();
+19 |     x.borrowed_mut(); //~ ERROR cannot borrow
+   |     ^
+
+error: cannot borrow immutable `Box` content `*x` as mutable
+  --> $DIR/borrowck-object-mutability.rs:29:5
+   |
+29 |     x.borrowed_mut(); //~ ERROR cannot borrow
+   |     ^
+
+error: aborting due to 2 previous errors
+

src/test/ui/span/mut-arg-hint.rs

@@ -0,0 +1,32 @@
+// Copyright 2015 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.
+
+trait B {
+    fn foo(mut a: &String) {
+        a.push_str("bar");
+    }
+}
+
+pub fn foo<'a>(mut a: &'a String) {
+    a.push_str("foo");
+}
+
+struct A {}
+
+impl A {
+    pub fn foo(mut a: &String) {
+        a.push_str("foo");
+    }
+}
+
+fn main() {
+    foo(&"a".to_string());
+    A::foo(&"a".to_string());
+}

src/test/ui/span/mut-arg-hint.stderr

@@ -0,0 +1,26 @@
+error: cannot borrow immutable borrowed content `*a` as mutable
+  --> $DIR/mut-arg-hint.rs:13:9
+   |
+12 |     fn foo(mut a: &String) {
+   |                   ------- use `&mut String` here to make mutable
+13 |         a.push_str("bar");
+   |         ^
+
+error: cannot borrow immutable borrowed content `*a` as mutable
+  --> $DIR/mut-arg-hint.rs:18:5
+   |
+17 | pub fn foo<'a>(mut a: &'a String) {
+   |                       ---------- use `&'a mut String` here to make mutable
+18 |     a.push_str("foo");
+   |     ^
+
+error: cannot borrow immutable borrowed content `*a` as mutable
+  --> $DIR/mut-arg-hint.rs:25:9
+   |
+24 |     pub fn foo(mut a: &String) {
+   |                       ------- use `&mut String` here to make mutable
+25 |         a.push_str("foo");
+   |         ^
+
+error: aborting due to 3 previous errors
+