Implement migrations for RFC 2229

[arora-aman]

Details over here: https://hackmd.io/71qq-IOpTNqzMkPpAI1dVg?view#Migration-Plan

• Basic first pass (Add lint for 2229 migrations rust#80629)
• Insignificant destructors
• Precise migrations (Implement the precise analysis pass for lint disjoint_capture_drop_reorder rust#81912)

[arora-aman]

For providing a suggestion:

• If closure contains a block, then just add the let _ = (...) at the start of the block
• else, add a { let _ = (...); at the start of the span and } at the end of the span as two separate suggestions.

Span suggestion examples:

• https://github.com/rust-lang/rust/blob/2656d6f363f671df23bc1770d994332c4098c3d0/compiler/rustc_ast_lowering/src/expr.rs#L1045-L1056
• https://github.com/rust-lang/rust/blob/2656d6f363f671df23bc1770d994332c4098c3d0/compiler/rustc_ast_lowering/src/path.rs#L233-L247
• https://github.com/rust-lang/rust/blob/2656d6f363f671df23bc1770d994332c4098c3d0/compiler/rustc_lint/src/context.rs#L555-L562