stabilize const_float_bits_conv

This stabilizes `const_float_bits_conv`, and thus fixes rust-lang/rust#72447. With rust-lang/rust#128596 having landed, this is entirely a libs-only question now.

```rust
impl f32 {
    pub const fn to_bits(self) -> u32;
    pub const fn from_bits(v: u32) -> Self;
    pub const fn to_be_bytes(self) -> [u8; 4];
    pub const fn to_le_bytes(self) -> [u8; 4]
    pub const fn to_ne_bytes(self) -> [u8; 4];
    pub const fn from_be_bytes(bytes: [u8; 4]) -> Self;
    pub const fn from_le_bytes(bytes: [u8; 4]) -> Self;
    pub const fn from_ne_bytes(bytes: [u8; 4]) -> Self;
}

impl f64 {
    pub const fn to_bits(self) -> u64;
    pub const fn from_bits(v: u64) -> Self;
    pub const fn to_be_bytes(self) -> [u8; 8];
    pub const fn to_le_bytes(self) -> [u8; 8]
    pub const fn to_ne_bytes(self) -> [u8; 8];
    pub const fn from_be_bytes(bytes: [u8; 8]) -> Self;
    pub const fn from_le_bytes(bytes: [u8; 8]) -> Self;
    pub const fn from_ne_bytes(bytes: [u8; 8]) -> Self;
}
````

Cc `@rust-lang/wg-const-eval` `@rust-lang/libs-api`

…lints

This reverts the part of commit 19908ff in
subdirectory src/tools/clippy/clippy_lints.

Fix lint levels not getting overridden by attrs on `Stmt` nodes

Fixes #130142. See comments on the issue for context.

r? `@cjgillot`

…of path

…f paths

…stead of paths

…ead of path

…ostic items instead of paths

…ad of path

… of paths

…f path

… path

…f path

…m instead of path

…tead of path

…f paths

Disallow hidden references to mutable static

Closes #123060

Tracking:
- rust-lang/rust#123758