Rollup of 9 pull requests

[Centril]

Successful merges:

• Stabilize param_attrs in Rust 1.39.0 #64010 (Stabilize param_attrs in Rust 1.39.0)
• Document From trait for LhsExpr in parser #64136 (Document From trait for LhsExpr in parser)
• factor out pluralisation remains after #64280 #64342 (factor out pluralisation remains after Factor out pluralisation into syntax::errors #64280)
• Add long error explanation for E0312 #64347 (Add long error explanation for E0312)
• Add Compatibility Notes to RELEASES.md for 1.38.0 #64621 (Add Compatibility Notes to RELEASES.md for 1.38.0)
• remove the extra comma after the match arm #64632 (remove the extra comma after the match arm)
• No home directory on vxWorks #64640 (No home directory on vxWorks)
• Exempt extern "Rust" from improper_ctypes #64641 (Exempt extern "Rust" from improper_ctypes)
• Fix the span used to suggest avoiding for-loop moves #64642 (Fix the span used to suggest avoiding for-loop moves)

Failed merges:

r? @ghost