Only shown relevant type params in E0283 label

When we point at a binding to suggest giving it a type, erase all the
type for ADTs that have been resolved, leaving only the ones that could
not be inferred. For small shallow types this is not a problem, but for
big nested types with lots of params, this can otherwise cause a lot of
unnecessary visual output.

src/test/ui/const-generics/defaults/doesnt_infer.stderr

@@ -4,7 +4,7 @@ error[E0282]: type annotations needed for `Foo<{_: u32}>`
 LL |     let foo = Foo::foo();
    |         ---   ^^^^^^^^ cannot infer the value of const parameter `N`
    |         |
-   |         consider giving `foo` the explicit type `Foo<{_: u32}>`, where the type parameter `N` is specified
+   |         consider giving `foo` the explicit type `Foo<{_: _}>`, where the type parameter `N` is specified
 
 error: aborting due to previous error
 

src/test/ui/inference/erase-type-params-in-label.rs

@@ -0,0 +1,13 @@
+fn main() {
+    let foo = new(1, ""); //~ ERROR E0283
+}
+
+struct Bar<T, K, N: Default> {
+    t: T,
+    k: K,
+    n: N,
+}
+
+fn new<T, K, Z: Default>(t: T, k: K) -> Bar<T, K, Z> {
+    Bar { t, k, n: Default::default() }
+}

src/test/ui/inference/erase-type-params-in-label.stderr

@@ -0,0 +1,22 @@
+error[E0283]: type annotations needed for `Bar<i32, &str, Z>`
+  --> $DIR/erase-type-params-in-label.rs:2:15
+   |
+LL |     let foo = new(1, "");
+   |         ---   ^^^ cannot infer type for type parameter `Z` declared on the function `new`
+   |         |
+   |         consider giving `foo` the explicit type `Bar<_, _, Z>`, where the type parameter `Z` is specified
+   |
+   = note: cannot satisfy `_: Default`
+note: required by a bound in `new`
+  --> $DIR/erase-type-params-in-label.rs:11:17
+   |
+LL | fn new<T, K, Z: Default>(t: T, k: K) -> Bar<T, K, Z> {
+   |                 ^^^^^^^ required by this bound in `new`
+help: consider specifying the type arguments in the function call
+   |
+LL |     let foo = new::<T, K, Z>(1, "");
+   |                  +++++++++++
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0283`.

src/test/ui/inference/issue-83606.stderr

@@ -4,7 +4,7 @@ error[E0282]: type annotations needed for `[usize; _]`
 LL |     let _ = foo("foo"); //<- Do not suggest `foo::<N>("foo");`!
    |         -   ^^^ cannot infer the value of const parameter `N` declared on the function `foo`
    |         |
-   |         consider giving this pattern the explicit type `[usize; _]`, where the type parameter `N` is specified
+   |         consider giving this pattern the explicit type `[_; _]`, where the type parameter `N` is specified
 
 error: aborting due to previous error