Rollup of 7 pull requests

[Centril]

Successful merges:

• wasi: Implement more of the standard library #59619 (wasi: Implement more of the standard library)
• Never return uninhabited values at all #59639 (Never return uninhabited values at all)
• std: Upgrade compiler_builtins to fix wasi linkage #59643 (std: Upgrade compiler_builtins to fix wasi linkage)
• Be more direct about borrow contract #59663 (Be more direct about borrow contract)
• Updated the documentation of spin_loop and spin_loop_hint #59664 (Updated the documentation of spin_loop and spin_loop_hint)
• Updated the environment description in rustc. #59666 (Updated the environment description in rustc.)
• Revert rust-lld place changes #59672 (Revert rust-lld place changes)

Failed merges:

r? @ghost