Add new error codes and update tests

Author: GuillaumeGomez

src/librustc_typeck/check/method/suggest.rs

@@ -165,18 +165,21 @@ impl<'a, 'gcx, 'tcx> FnCtxt<'a, 'gcx, 'tcx> {
                                                .. }) => {
                 let tcx = self.tcx;
 
-                let mut err = self.type_error_struct(span,
-                                                     |actual| {
-                    format!("no {} named `{}` found for type `{}` in the current scope",
-                            if mode == Mode::MethodCall {
-                                "method"
-                            } else {
-                                "associated item"
-                            },
-                            item_name,
-                            actual)
-                },
-                                                     rcvr_ty);
+                let actual = self.resolve_type_vars_if_possible(&rcvr_ty);
+                let mut err = if !actual.references_error() {
+                    struct_span_err!(tcx.sess, span, E0599,
+                                     "no {} named `{}` found for type `{}` in the \
+                                      current scope",
+                                     if mode == Mode::MethodCall {
+                                         "method"
+                                     } else {
+                                         "associated item"
+                                     },
+                                     item_name,
+                                     self.ty_to_string(actual))
+                } else {
+                    self.tcx.sess.diagnostic().struct_dummy()
+                };
 
                 // If the method name is the name of a field with a function or closure type,
                 // give a helping note that it has to be called as (x.f)(...).

src/librustc_typeck/diagnostics.rs

@@ -4005,7 +4005,7 @@ details.
 [issue #33685]: https://github.com/rust-lang/rust/issues/33685
 "##,
 
-    E0582: r##"
+E0582: r##"
 A lifetime appears only in an associated-type binding,
 and not in the input types to the trait.
 
@@ -4042,6 +4042,16 @@ details.
 [issue #33685]: https://github.com/rust-lang/rust/issues/33685
 "##,
 
+E0599: r##"
+```compile_fail,E0599
+struct Mouth;
+
+let x = Mouth;
+x.chocolate(); // error: no method named `chocolate` found for type `Mouth`
+               //        in the current scope
+```
+"##,
+
 }
 
 register_diagnostics! {

src/test/ui/codemap_tests/huge_multispan_highlight.stderr

@@ -1,4 +1,4 @@
-error: cannot borrow immutable local variable `x` as mutable
+error[E0596]: cannot borrow immutable local variable `x` as mutable
    --> $DIR/huge_multispan_highlight.rs:100:18
     |
 12  |     let x = "foo";

src/test/ui/did_you_mean/issue-31424.stderr

@@ -1,4 +1,4 @@
-error: cannot borrow immutable argument `self` as mutable
+error[E0596]: cannot borrow immutable argument `self` as mutable
   --> $DIR/issue-31424.rs:17:15
    |
 17 |         (&mut self).bar();
@@ -7,7 +7,7 @@ error: cannot borrow immutable argument `self` as mutable
    |               try removing `&mut` here
    |               cannot reborrow mutably
 
-error: cannot borrow immutable argument `self` as mutable
+error[E0596]: cannot borrow immutable argument `self` as mutable
   --> $DIR/issue-31424.rs:23:15
    |
 22 |     fn bar(self: &mut Self) {

src/test/ui/did_you_mean/issue-34126.stderr

@@ -1,4 +1,4 @@
-error: cannot borrow immutable argument `self` as mutable
+error[E0596]: cannot borrow immutable argument `self` as mutable
   --> $DIR/issue-34126.rs:16:23
    |
 16 |         self.run(&mut self);

src/test/ui/did_you_mean/issue-34337.stderr

@@ -1,4 +1,4 @@
-error: cannot borrow immutable local variable `key` as mutable
+error[E0596]: cannot borrow immutable local variable `key` as mutable
   --> $DIR/issue-34337.rs:16:14
    |
 16 |     get(&mut key);

src/test/ui/did_you_mean/issue-35937.stderr

@@ -1,20 +1,20 @@
-error: cannot borrow immutable field `f.v` as mutable
+error[E0596]: cannot borrow immutable field `f.v` as mutable
   --> $DIR/issue-35937.rs:17:5
    |
 16 |     let f = Foo { v: Vec::new() };
    |         - consider changing this to `mut f`
 17 |     f.v.push("cat".to_string());
    |     ^^^ cannot mutably borrow immutable field
 
-error: cannot assign to immutable field `s.x`
+error[E0594]: cannot assign to immutable field `s.x`
   --> $DIR/issue-35937.rs:26:5
    |
 25 |     let s = S { x: 42 };
    |         - consider changing this to `mut s`
 26 |     s.x += 1;
    |     ^^^^^^^^ cannot mutably borrow immutable field
 
-error: cannot assign to immutable field `s.x`
+error[E0594]: cannot assign to immutable field `s.x`
   --> $DIR/issue-35937.rs:30:5
    |
 29 | fn bar(s: S) {

src/test/ui/did_you_mean/issue-37139.stderr

@@ -1,4 +1,4 @@
-error: cannot borrow immutable local variable `x` as mutable
+error[E0596]: cannot borrow immutable local variable `x` as mutable
   --> $DIR/issue-37139.rs:22:23
    |
 22 |             test(&mut x);

src/test/ui/did_you_mean/issue-38147-2.stderr

@@ -1,4 +1,4 @@
-error: cannot borrow immutable borrowed content `*self.s` as mutable
+error[E0596]: cannot borrow immutable borrowed content `*self.s` as mutable
   --> $DIR/issue-38147-2.rs:17:9
    |
 12 |     s: &'a String

src/test/ui/did_you_mean/issue-38147-3.stderr

@@ -1,4 +1,4 @@
-error: cannot borrow immutable borrowed content `*self.s` as mutable
+error[E0596]: cannot borrow immutable borrowed content `*self.s` as mutable
   --> $DIR/issue-38147-3.rs:17:9
    |
 12 |     s: &'a String