Reorder fullfillment errors to keep more interesting ones first

In `report_fullfillment_errors` push back `T: Sized`, `T: WellFormed`
and coercion errors to the end of the list. The pre-existing
deduplication logic eliminates redundant errors better that way, keeping
the resulting output with fewer errors than before, while also having
more detail.

6 files changed, 27 insertions, 19 deletions

diff --git a/tests/ui/issues/issue-12187-1.stderr b/tests/ui/issues/issue-12187-1.stderr
index 806b7f0ac05..d2a6a96082e 100644
--- a/tests/ui/issues/issue-12187-1.stderr
+++ b/tests/ui/issues/issue-12187-1.stderr
@@ -2,9 +2,9 @@ error[E0282]: type annotations needed for `&T`
   --> $DIR/issue-12187-1.rs:6:9
    |
 LL |     let &v = new();
-   |         ^^
+   |         ^^   ----- type must be known at this point
    |
-help: consider giving this pattern a type, where the placeholders `_` are specified
+help: consider giving this pattern a type, where the type for type parameter `T` is specified
    |
 LL |     let &v: &T = new();
    |           ++++
diff --git a/tests/ui/issues/issue-12187-2.stderr b/tests/ui/issues/issue-12187-2.stderr
index a1fa0a2b002..ac75ebb4256 100644
--- a/tests/ui/issues/issue-12187-2.stderr
+++ b/tests/ui/issues/issue-12187-2.stderr
@@ -2,9 +2,9 @@ error[E0282]: type annotations needed for `&T`
   --> $DIR/issue-12187-2.rs:6:9
    |
 LL |     let &v = new();
-   |         ^^
+   |         ^^   ----- type must be known at this point
    |
-help: consider giving this pattern a type, where the placeholders `_` are specified
+help: consider giving this pattern a type, where the type for type parameter `T` is specified
    |
 LL |     let &v: &T = new();
    |           ++++
diff --git a/tests/ui/issues/issue-16966.stderr b/tests/ui/issues/issue-16966.stderr
index 8c92505b5eb..c53707c5d69 100644
--- a/tests/ui/issues/issue-16966.stderr
+++ b/tests/ui/issues/issue-16966.stderr
@@ -1,9 +1,16 @@
-error[E0282]: type annotations needed
+error[E0283]: type annotations needed
   --> $DIR/issue-16966.rs:2:12
    |
 LL |     panic!(std::default::Default::default());
-   |            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type
+   |     -------^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^-
+   |     |      |
+   |     |      cannot infer type
+   |     required by a bound introduced by this call
+   |
+   = note: cannot satisfy `_: Any`
+note: required by a bound in `begin_panic`
+  --> $SRC_DIR/std/src/panicking.rs:LL:COL
 
 error: aborting due to previous error
 
-For more information about this error, try `rustc --explain E0282`.
+For more information about this error, try `rustc --explain E0283`.
diff --git a/tests/ui/issues/issue-17551.stderr b/tests/ui/issues/issue-17551.stderr
index 5f45a2f8443..3a8f569a3a5 100644
--- a/tests/ui/issues/issue-17551.stderr
+++ b/tests/ui/issues/issue-17551.stderr
@@ -2,7 +2,7 @@ error[E0282]: type annotations needed for `B<T>`
   --> $DIR/issue-17551.rs:6:9
    |
 LL |     let foo = B(marker::PhantomData);
-   |         ^^^
+   |         ^^^     ------------------- type must be known at this point
    |
 help: consider giving `foo` an explicit type, where the type for type parameter `T` is specified
    |
diff --git a/tests/ui/issues/issue-24036.stderr b/tests/ui/issues/issue-24036.stderr
index a425816cdeb..184383b7369 100644
--- a/tests/ui/issues/issue-24036.stderr
+++ b/tests/ui/issues/issue-24036.stderr
@@ -11,12 +11,13 @@ LL |     x = |c| c + 1;
    = note: no two closures, even if identical, have the same type
    = help: consider boxing your closure and/or using it as a trait object
 
-error[E0282]: type annotations needed
+error[E0284]: type annotations needed
   --> $DIR/issue-24036.rs:9:15
    |
 LL |         1 => |c| c + 1,
-   |               ^
+   |               ^    - type must be known at this point
    |
+   = note: cannot satisfy `<_ as Add<i32>>::Output == _`
 help: consider giving this closure parameter an explicit type
    |
 LL |         1 => |c: /* Type */| c + 1,
@@ -24,5 +25,5 @@ LL |         1 => |c: /* Type */| c + 1,
 
 error: aborting due to 2 previous errors
 
-Some errors have detailed explanations: E0282, E0308.
-For more information about an error, try `rustc --explain E0282`.
+Some errors have detailed explanations: E0284, E0308.
+For more information about an error, try `rustc --explain E0284`.
diff --git a/tests/ui/issues/issue-24446.stderr b/tests/ui/issues/issue-24446.stderr
index 4afb87c4825..72d528f1619 100644
--- a/tests/ui/issues/issue-24446.stderr
+++ b/tests/ui/issues/issue-24446.stderr
@@ -1,19 +1,19 @@
-error[E0277]: the size for values of type `(dyn Fn() -> u32 + 'static)` cannot be known at compilation time
+error[E0277]: `(dyn Fn() -> u32 + 'static)` cannot be shared between threads safely
   --> $DIR/issue-24446.rs:2:17
    |
 LL |     static foo: dyn Fn() -> u32 = || -> u32 {
-   |                 ^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
+   |                 ^^^^^^^^^^^^^^^ `(dyn Fn() -> u32 + 'static)` cannot be shared between threads safely
    |
-   = help: the trait `Sized` is not implemented for `(dyn Fn() -> u32 + 'static)`
+   = help: the trait `Sync` is not implemented for `(dyn Fn() -> u32 + 'static)`
+   = note: shared static variables must have a type that implements `Sync`
 
-error[E0277]: `(dyn Fn() -> u32 + 'static)` cannot be shared between threads safely
+error[E0277]: the size for values of type `(dyn Fn() -> u32 + 'static)` cannot be known at compilation time
   --> $DIR/issue-24446.rs:2:17
    |
 LL |     static foo: dyn Fn() -> u32 = || -> u32 {
-   |                 ^^^^^^^^^^^^^^^ `(dyn Fn() -> u32 + 'static)` cannot be shared between threads safely
+   |                 ^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |
-   = help: the trait `Sync` is not implemented for `(dyn Fn() -> u32 + 'static)`
-   = note: shared static variables must have a type that implements `Sync`
+   = help: the trait `Sized` is not implemented for `(dyn Fn() -> u32 + 'static)`
 
 error: aborting due to 2 previous errors