Rollup merge of rust-lang#143301 - Kivooeo:tf26, r=tgross35

`tests/ui`: A New Order [26/N]

> [!NOTE]
>
> Intermediate commits are intended to help review, but will be squashed prior to merge.

Some `tests/ui/` housekeeping, to trim down number of tests directly under `tests/ui/`. Part of rust-lang#133895.

r? `@tgross35`

Author: tgross35

tests/ui/auxiliary/svh-a-base.rs

@@ -1,5 +1,5 @@
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:30:28
+  --> $DIR/super-let-lifetime-and-drop.rs:30:28
    |
 LL |             super let b = DropMe(&mut x);
    |                                  ------ `x` is borrowed here
@@ -11,7 +11,7 @@ LL |     }
    |     - borrow might be used here, when `b` is dropped and runs the `Drop` code for type `DropMe`
 
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:46:28
+  --> $DIR/super-let-lifetime-and-drop.rs:46:28
    |
 LL |             super let b = &DropMe(&mut x);
    |                            --------------
@@ -26,7 +26,7 @@ LL |     }
    |     - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `DropMe`
 
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:64:32
+  --> $DIR/super-let-lifetime-and-drop.rs:64:32
    |
 LL |             super let b = identity(&DropMe(&mut x));
    |                                     --------------
@@ -40,7 +40,7 @@ LL |         };
    |          - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `DropMe`
 
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:87:36
+  --> $DIR/super-let-lifetime-and-drop.rs:87:36
    |
 LL |                 super let b = identity(&DropMe(&mut x));
    |                                         --------------
@@ -55,7 +55,7 @@ LL |         ));
    |           - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `DropMe`
 
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:107:28
+  --> $DIR/super-let-lifetime-and-drop.rs:107:28
    |
 LL |                 super let b = DropMe(&mut x);
    |                                      ------ `x` is borrowed here
@@ -67,7 +67,7 @@ LL |     }
    |     - borrow might be used here, when `b` is dropped and runs the `Drop` code for type `DropMe`
 
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:125:28
+  --> $DIR/super-let-lifetime-and-drop.rs:125:28
    |
 LL |             super let b = DropMe(&mut x);
    |                                  ------ `x` is borrowed here
@@ -79,7 +79,7 @@ LL |     }
    |     - borrow might be used here, when `b` is dropped and runs the `Drop` code for type `DropMe`
 
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:143:28
+  --> $DIR/super-let-lifetime-and-drop.rs:143:28
    |
 LL |             super let b = DropMe(&mut x);
    |                                  ------ `x` is borrowed here
@@ -91,7 +91,7 @@ LL |     }
    |     - borrow might be used here, when `b` is dropped and runs the `Drop` code for type `DropMe`
 
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:159:28
+  --> $DIR/super-let-lifetime-and-drop.rs:159:28
    |
 LL |             b = DropMe(&mut x);
    |                        ------ `x` is borrowed here
@@ -102,7 +102,7 @@ LL |         drop(a);
    |              - borrow later used here
 
 error[E0716]: temporary value dropped while borrowed
-  --> $DIR/super-let.rs:172:33
+  --> $DIR/super-let-lifetime-and-drop.rs:172:33
    |
 LL |         #[cfg(borrowck)] { a = &String::from("asdf"); };
    |                                 ^^^^^^^^^^^^^^^^^^^^- temporary value is freed at the end of this statement
@@ -115,7 +115,7 @@ LL |         let _ = a;
    = note: consider using a `let` binding to create a longer lived value
 
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:206:28
+  --> $DIR/super-let-lifetime-and-drop.rs:206:28
    |
 LL |                     super let d = &DropMe(&mut x);
    |                                    --------------
@@ -130,7 +130,7 @@ LL |     }
    |     - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `DropMe`
 
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:227:32
+  --> $DIR/super-let-lifetime-and-drop.rs:227:32
    |
 LL |                     super let d = identity(&DropMe(&mut x));
    |                                             --------------
@@ -145,7 +145,7 @@ LL |         };
    |          - ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `DropMe`
 
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:246:28
+  --> $DIR/super-let-lifetime-and-drop.rs:246:28
    |
 LL |             super let b = DropMe(&mut x);
    |                                  ------ `x` is borrowed here
@@ -157,7 +157,7 @@ LL |     }
    |     - borrow might be used here, when `b` is dropped and runs the `Drop` code for type `DropMe`
 
 error[E0506]: cannot assign to `x` because it is borrowed
-  --> $DIR/super-let.rs:263:28
+  --> $DIR/super-let-lifetime-and-drop.rs:263:28
    |
 LL |             let dropme = Some(DropMe(&mut x));
    |                                      ------ `x` is borrowed here

tests/ui/auxiliary/svh-b.rs

@@ -1,5 +1,10 @@
+//! This test verifies that a direct non-primitive cast from an enum to an integer type
+//! is correctly disallowed, even when a `From` implementation exists for that enum.
+
 //@ run-rustfix
+
 #![allow(dead_code, unused_variables)]
+
 enum NonNullary {
     Nullary,
     Other(isize),
@@ -16,5 +21,7 @@ impl From<NonNullary> for isize {
 
 fn main() {
     let v = NonNullary::Nullary;
-    let val = v as isize; //~ ERROR non-primitive cast: `NonNullary` as `isize` [E0605]
+    let val = isize::from(v);
+    //~^ ERROR non-primitive cast: `NonNullary` as `isize` [E0605]
+    //~| HELP consider using the `From` trait instead
 }

tests/ui/super-let.borrowck.stderr renamed to tests/ui/borrowck/super-let-lifetime-and-drop.borrowck.stderr

@@ -1,5 +1,10 @@
+//! This test verifies that a direct non-primitive cast from an enum to an integer type
+//! is correctly disallowed, even when a `From` implementation exists for that enum.
+
 //@ run-rustfix
+
 #![allow(dead_code, unused_variables)]
+
 enum NonNullary {
     Nullary,
     Other(isize),
@@ -16,5 +21,7 @@ impl From<NonNullary> for isize {
 
 fn main() {
     let v = NonNullary::Nullary;
-    let val = isize::from(v); //~ ERROR non-primitive cast: `NonNullary` as `isize` [E0605]
+    let val = v as isize;
+    //~^ ERROR non-primitive cast: `NonNullary` as `isize` [E0605]
+    //~| HELP consider using the `From` trait instead
 }

tests/ui/super-let.rs renamed to tests/ui/borrowck/super-let-lifetime-and-drop.rs

@@ -1,5 +1,5 @@
 error[E0605]: non-primitive cast: `NonNullary` as `isize`
-  --> $DIR/tag-variant-cast-non-nullary.rs:19:15
+  --> $DIR/cast-enum-to-primitive-error.rs:24:15
    |
 LL |     let val = v as isize;
    |               ^^^^^^^^^^ an `as` expression can be used to convert enum types to numeric types only if the enum type is unit-only or field-less

tests/ui/tag-variant-cast-non-nullary.rs renamed to tests/ui/cast/cast-enum-to-primitive-error.fixed

@@ -1,5 +1,7 @@
+//! This test checks that various forms of "trivial" casts and coercions
+//! can be explicitly performed using the `as` keyword without compilation errors.
+
 //@ run-pass
-// Test that all coercions can actually be done using casts (modulo the lints).
 
 #![allow(trivial_casts, trivial_numeric_casts)]
 

tests/ui/tag-variant-cast-non-nullary.fixed renamed to tests/ui/cast/cast-enum-to-primitive-error.rs

@@ -1,5 +1,5 @@
 warning: method `foo` is never used
-  --> $DIR/trivial_casts-rpass.rs:7:8
+  --> $DIR/coercion-as-explicit-cast.rs:9:8
    |
 LL | trait Foo {
    |       --- method in this trait

tests/ui/tag-variant-cast-non-nullary.stderr renamed to tests/ui/cast/cast-enum-to-primitive-error.stderr

@@ -0,0 +1,15 @@
+//! This test checks that unused generics are rejected by compiler
+
+enum Quux<T> {
+    //~^ ERROR: parameter `T` is never used
+    Bar,
+}
+
+fn foo(c: Quux) {
+    //~^ ERROR missing generics for enum `Quux`
+    assert!((false));
+}
+
+fn main() {
+    panic!();
+}