…iaskrgr

Rollup of 9 pull requests

Successful merges:

 - rust-lang#116740 (dont ICE when ConstKind::Expr for is_const_evaluatable)
 - rust-lang#117914 (On borrow return type, suggest borrowing from arg or owned return type)
 - rust-lang#117927 (Clarify how to choose a FutureIncompatibilityReason variant.)
 - rust-lang#118855 (Improve an error involving attribute values.)
 - rust-lang#118856 (rustdoc-search: clean up parser)
 - rust-lang#118865 (rustc_codegen_llvm: Enforce `rustc::potential_query_instability` lint)
 - rust-lang#118866 (llvm-wrapper: adapt for LLVM API change)
 - rust-lang#118868 (Correctly gate the parsing of match arms without body)
 - rust-lang#118877 (tests: CGU tests require build-pass, not check-pass (remove FIXME))

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of rust-lang#118855 - nnethercote:improve-attribute-value-error, r=compiler-errors,petrochenkov

Improve an error involving attribute values.

Attribute values must be literals. The error you get when that doesn't hold is pretty bad, e.g.:
```
unexpected expression: 1 + 1
```
You also get the same error if the attribute value is a literal, but an invalid literal, e.g.:
```
unexpected expression: "foo"suffix
```

This commit does two things.
- Changes the error message to "attribute value must be a literal", which gives a better idea of what the problem is and how to fix it. It also no longer prints the invalid expression, because the carets below highlight it anyway.
- Separates the "not a literal" case from the "invalid literal" case. Which means invalid literals now get the specific error at the literal level, rather than at the attribute level.

r? `@compiler-errors`