We've investigated one reason why debugging information often goes wrong at https://reviews.llvm.org/D152095.
> LLVM can't handle IR where subprogram definitions are nested within DICompositeType when doing LTO builds,
> because there's no good way to cross the CU boundary to insert a nested DISubprogram definition in one CU into a type defined in another CU.

Make Const more useful in smir

Since rust-lang#114587 is merged, we can make use of what we built and make Const more useful by making it not `Opaque`

r? `@spastorino`

…, r=compiler-errors

fixed *const [type error] does not implement the Copy trait

Removes "error: arguments for inline assembly must be copyable" when moving an unknown type

Fixes: rust-lang#113788

…isubprogram, r=cuviper

DebugInfo: Updates test cases that add method declarations.

We've investigated one reason why debugging information often goes wrong at https://reviews.llvm.org/D152095.
> LLVM can't handle IR where subprogram definitions are nested within DICompositeType when doing LTO builds, because there's no good way to cross the CU boundary to insert a nested DISubprogram definition in one CU into a type defined in another CU.

In rust-lang#111167, we added a declaration for the DISubprogram for the method. This PR completes this test case.

stream history: https://rust-lang.zulipchat.com/#narrow/stream/187780-t-compiler.2Fwg-llvm/topic/Dwarf.20CUs/near/384269475.

Update books

## rust-lang/book

3 commits in 668c64760b5c7ea654facb4ba5fe9faddfda27cc..72187f5cd0beaaa9c6f584156bcd88f921871e83
2023-08-04 14:42:07 UTC to 2023-08-03 13:36:44 UTC

- redirects: change link for the `#![no_std]` tutorial (rust-lang/book#3705)
- [chpt10.2] - Small wording changes (rust-lang/book#3724)
- Improve sentence (rust-lang/book#3725)

## rust-embedded/book

1 commits in 1e5556dd1b864109985d5871616ae6b9164bcead..99ad2847b865e96d8ae7b333d3ee96963557e621
2023-08-11 06:31:04 UTC to 2023-08-11 06:31:04 UTC

- Fix a small typo in qemu.md (rust-embedded/book#359)

## rust-lang/nomicon

1 commits in 302b995bcb24b70fd883980fd174738c3a10b705..388750b081c0893c275044d37203f97709e058ba
2023-08-10 21:15:21 UTC to 2023-08-10 21:15:21 UTC

- Document thiscall abi (rust-lang/nomicon#311)

## rust-lang/reference

10 commits in 1ea0178266b3f3f613b0fabdaf16a83961c99cdb..d43038932adeb16ada80e206d4c073d851298101
2023-08-12 19:07:28 UTC to 2023-07-16 20:12:46 UTC

- Document thiscall abi (rust-lang/reference#1092)
- add section about implied bounds (rust-lang/reference#1261)
- Clearly specify the `instruction_set` effects (rust-lang/reference#1307)
- Fix merge queue building twice. (rust-lang/reference#1383)
- Clarify UB around immutability & mutation (rust-lang/reference#1385)
- mention the extra const UB (rust-lang/reference#1273)
- Operator expressions: make the note about division by zero clearer. (rust-lang/reference#1384)
- Make unsafe keyword docs less confusing (rust-lang/reference#1379)
- Say that division by zero for primitive types panics (rust-lang/reference#1382)
- Add CI trigger for merge queues. (rust-lang/reference#1381)

## rust-lang/rust-by-example

3 commits in 8a87926a985ce32ca1fad1be4008ee161a0b91eb..07e0df2f006e59d171c6bf3cafa9d61dbeb520d8
2023-07-24 11:37:55 UTC to 2023-07-24 11:35:36 UTC

- Added attribute unused_labels - fixed warning. (rust-lang/rust-by-example#1729)
- more explanation about panic (rust-lang/rust-by-example#1728)
- chore: add the portuguese version of this project to `readme.md` (rust-lang/rust-by-example#1727)

## rust-lang/rustc-dev-guide

31 commits in b5a12d9..b123ab4
2023-08-14 08:34:59 UTC to 2023-07-11 06:02:34 UTC

- fix: stabilize debugger_visualizer (rust-lang/rustc-dev-guide#1766)
- feat(part-5-intro): make "Part 5" obvious (rust-lang/rustc-dev-guide#1753)
- Update from `#[warn_]` to `#[warning]` diagnostic attributes (rust-lang/rustc-dev-guide#1765)
- Add RPITIT documentation (rust-lang/rustc-dev-guide#1764)
- fix(visitor.md): fix a type name in a code sample (rust-lang/rustc-dev-guide#1762)
- fix(name-resolution): remove unnecessary closing paranthesis (rust-lang/rustc-dev-guide#1760)
- fix(macro-expansion.md): fix the article `an` to `a` (rust-lang/rustc-dev-guide#1759)
- fix(serialization.md): fix the name of a derive macro (rust-lang/rustc-dev-guide#1756)
- fix(serialization.md): add a necessary plural suffix (rust-lang/rustc-dev-guide#1757)
- fix(salsa.md): add punctuation to prevent confusion (rust-lang/rustc-dev-guide#1754)
- fix(salsa.md): remove duplicate "To Be" verb (rust-lang/rustc-dev-guide#1755)
- feat(fuzzing.md): make `halfempty` word a link (rust-lang/rustc-dev-guide#1750)
- fix(about.md): use `a` instead of `an` (rust-lang/rustc-dev-guide#1751)
- refactor(git.md): make git-scm links clickable (rust-lang/rustc-dev-guide#1747)
- fix(walkthrough.md) add a comma operator to eliminate ambiguity (rust-lang/rustc-dev-guide#1749)
- fix(git.md): remove a confusing end of sentence character (rust-lang/rustc-dev-guide#1748)
- refactor(profiling/with_perf): remove a wrong to be verb (rust-lang/rustc-dev-guide#1746)
- refactor(tests/headers): remove duplicate list item (rust-lang/rustc-dev-guide#1745)
- refactor(test/headers.md): make the meaning more obvious (rust-lang/rustc-dev-guide#1744)
- refactor(tests/ui): remove unnecessary duplicate word (rust-lang/rustc-dev-guide#1743)
- refactor(compiletest): remove unnecessary duplicate word (rust-lang/rustc-dev-guide#1742)
- generic_arguments.md: substs -> GenericArgs (rust-lang/rustc-dev-guide#1741)
- fix(suggested): remove an unnecessary and confusing statement (rust-lang/rustc-dev-guide#1739)
- fix(how-to-build-and-run): fix a typo ("fromer" -> "former") (rust-lang/rustc-dev-guide#1736)
- fix(how-to-build-and-run): remove a wrong paragraph (rust-lang/rustc-dev-guide#1735)
- coverage code has moved (rust-lang/rustc-dev-guide#1728)
- linked issue is closed (rust-lang/rustc-dev-guide#1729)
- remove duplicate reference in about-this-guide.md (rust-lang/rustc-dev-guide#1734)
- Explain more in depth what early and late bound generic parameters are (rust-lang/rustc-dev-guide#1732)
- add section for normalization with the new solver (rust-lang/rustc-dev-guide#1731)
- Improve cleanup-crew.md with an example post (rust-lang/rustc-dev-guide#1730)

Remove unnecessary FIXME

Found this while browsing rustc, I traced it back to rust-lang#27893 when MIR first introduced, some time passed since then and I think this FIXME is no longer necessary.