Rollup merge of #130953 - workingjubilee:rename-a-few-ctypes-tests, r=fee1-dead

Rename a few tests to make tidy happier

A somewhat random smattering of tests that I have recently looked at, and thus had cause to research and write down the reason for their existence.

src/tools/tidy/src/issues.txt

@@ -795,7 +795,6 @@ ui/consts/issue-68684.rs
 ui/consts/issue-69191-ice-on-uninhabited-enum-field.rs
 ui/consts/issue-69310-array-size-lit-wrong-ty.rs
 ui/consts/issue-69312.rs
-ui/consts/issue-69488.rs
 ui/consts/issue-69532.rs
 ui/consts/issue-6991.rs
 ui/consts/issue-70773-mir-typeck-lt-norm.rs
@@ -2745,14 +2744,12 @@ ui/lint/issue-111359.rs
 ui/lint/issue-112489.rs
 ui/lint/issue-117949.rs
 ui/lint/issue-121070-let-range.rs
-ui/lint/issue-14309.rs
 ui/lint/issue-14837.rs
 ui/lint/issue-17718-const-naming.rs
 ui/lint/issue-1866.rs
 ui/lint/issue-19102.rs
 ui/lint/issue-20343.rs
 ui/lint/issue-30302.rs
-ui/lint/issue-34798.rs
 ui/lint/issue-35075.rs
 ui/lint/issue-47775-nested-macro-unnecessary-parens-arg.rs
 ui/lint/issue-49588-non-shorthand-field-patterns-in-pattern-macro.rs

tests/ui/consts/load-preserves-partial-init.rs

@@ -1,6 +1,9 @@
 //@ run-pass
 
 #![feature(const_ptr_write)]
+// issue: https://github.com/rust-lang/rust/issues/69488
+// Loads of partially-initialized data could produce completely-uninitialized results.
+// Test to make sure that we no longer do such a "deinitializing" load.
 
 // Or, equivalently: `MaybeUninit`.
 pub union BagOfBits<T: Copy> {

tests/ui/lint/improper_ctypes/allow-phantomdata-in-ffi.rs

@@ -1,6 +1,8 @@
 //@ run-pass
 #![forbid(improper_ctypes)]
 #![allow(dead_code)]
+// issue https://github.com/rust-lang/rust/issues/34798
+// We allow PhantomData in FFI so bindgen can bind templated C++ structs with "unused generic args"
 
 #[repr(C)]
 pub struct Foo {

tests/ui/lint/improper_ctypes/repr-rust-is-undefined.rs

@@ -1,6 +1,10 @@
 #![deny(improper_ctypes)]
 #![allow(dead_code)]
 
+// issue https://github.com/rust-lang/rust/issues/14309
+// Validates we lint on repr(Rust) structs and not repr(C) structs in FFI, to implement RFC 79:
+// https://rust-lang.github.io/rfcs/0079-undefined-struct-layout.html
+
 struct A {
     x: i32
 }

tests/ui/lint/improper_ctypes/repr-rust-is-undefined.stderr

@@ -1,5 +1,5 @@
 error: `extern` block uses type `A`, which is not FFI-safe
-  --> $DIR/issue-14309.rs:30:15
+  --> $DIR/repr-rust-is-undefined.rs:34:15
    |
 LL |     fn foo(x: A);
    |               ^ not FFI-safe
@@ -7,18 +7,18 @@ LL |     fn foo(x: A);
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 note: the type is defined here
-  --> $DIR/issue-14309.rs:4:1
+  --> $DIR/repr-rust-is-undefined.rs:8:1
    |
 LL | struct A {
    | ^^^^^^^^
 note: the lint level is defined here
-  --> $DIR/issue-14309.rs:1:9
+  --> $DIR/repr-rust-is-undefined.rs:1:9
    |
 LL | #![deny(improper_ctypes)]
    |         ^^^^^^^^^^^^^^^
 
 error: `extern` block uses type `A`, which is not FFI-safe
-  --> $DIR/issue-14309.rs:31:15
+  --> $DIR/repr-rust-is-undefined.rs:35:15
    |
 LL |     fn bar(x: B);
    |               ^ not FFI-safe
@@ -26,13 +26,13 @@ LL |     fn bar(x: B);
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 note: the type is defined here
-  --> $DIR/issue-14309.rs:4:1
+  --> $DIR/repr-rust-is-undefined.rs:8:1
    |
 LL | struct A {
    | ^^^^^^^^
 
 error: `extern` block uses type `A`, which is not FFI-safe
-  --> $DIR/issue-14309.rs:33:15
+  --> $DIR/repr-rust-is-undefined.rs:37:15
    |
 LL |     fn qux(x: A2);
    |               ^^ not FFI-safe
@@ -40,13 +40,13 @@ LL |     fn qux(x: A2);
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 note: the type is defined here
-  --> $DIR/issue-14309.rs:4:1
+  --> $DIR/repr-rust-is-undefined.rs:8:1
    |
 LL | struct A {
    | ^^^^^^^^
 
 error: `extern` block uses type `A`, which is not FFI-safe
-  --> $DIR/issue-14309.rs:34:16
+  --> $DIR/repr-rust-is-undefined.rs:38:16
    |
 LL |     fn quux(x: B2);
    |                ^^ not FFI-safe
@@ -54,13 +54,13 @@ LL |     fn quux(x: B2);
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 note: the type is defined here
-  --> $DIR/issue-14309.rs:4:1
+  --> $DIR/repr-rust-is-undefined.rs:8:1
    |
 LL | struct A {
    | ^^^^^^^^
 
 error: `extern` block uses type `A`, which is not FFI-safe
-  --> $DIR/issue-14309.rs:36:16
+  --> $DIR/repr-rust-is-undefined.rs:40:16
    |
 LL |     fn fred(x: D);
    |                ^ not FFI-safe
@@ -68,7 +68,7 @@ LL |     fn fred(x: D);
    = help: consider adding a `#[repr(C)]` or `#[repr(transparent)]` attribute to this struct
    = note: this struct has unspecified layout
 note: the type is defined here
-  --> $DIR/issue-14309.rs:4:1
+  --> $DIR/repr-rust-is-undefined.rs:8:1
    |
 LL | struct A {
    | ^^^^^^^^