Fix some more clippy warnings
Found while working on https://github.com/rust-lang/rust/pull/77351. It turns out that `x.py clippy --fix` does work on that branch as long as you pass `CARGOFLAGS=--lib`.
Avoid BorrowMutError with RUSTC_LOG=debug
```console
$ touch empty.rs
$ env RUSTC_LOG=debug rustc +stage1 --crate-type=lib empty.rs
```
Fails with a `BorrowMutError` because source map files are already
borrowed while `features_query` attempts to format a log message
containing a span.
Release the borrow before the query to avoid the issue.
Simplify a nested bool match
Logically this first eliminates the innermost match by merging the patterns.
Then, in a second step, turns the newly innermost match into a `matches!` call.
Always record reference to binding in match if guards
When encountering a binding from a `match` pattern in its `if` guard when computing a generator's interior types, we must always record the type of a reference to the binding because of how `if` guards are lowered to MIR. This was missed in #75213 because the binding in that test case was autorefed and we recorded that adjusted type anyway.
Fixes#78366
[resolve] Use `unwrap_or_else` instead of `unwrap_or` in a hot path
This improves the performance of the `resolve_crate` function by 30% for
a very large single file crate with auto-generated C bindings.
cc `@rylev`
Directly casting the opaque pointer was [reported] to cause an
"incomplete type" error with GCC 9.3:
```
llvm-wrapper/RustWrapper.cpp:939:31: required from here
/usr/include/c++/9.3/type_traits:1301:12: error: invalid use of incomplete type 'struct LLVMOpaqueMetadata'
1301 | struct is_base_of
| ^~~~~~~~~~
In file included from [...]/rust/src/llvm-project/llvm/include/llvm-c/BitReader.h:23,
from llvm-wrapper/LLVMWrapper.h:1,
from llvm-wrapper/RustWrapper.cpp:1:
[...]/rust/src/llvm-project/llvm/include/llvm-c/Types.h:89:16: note: forward declaration of 'struct LLVMOpaqueMetadata'
89 | typedef struct LLVMOpaqueMetadata *LLVMMetadataRef;
| ^~~~~~~~~~~~~~~~~~
```
[reported]: https://zulip-archive.rust-lang.org/182449tcompilerhelp/12215halprustcllvmbuildfail.html#214915124
A simple `unwrap` fixes the issue.
Update Clippy - temporary_cstring_as_ptr deprecation
In #75671 `clippy::temporary_cstr_as_ptr` was removed instead of being deprecated. This will trigger an error (unknown lint) for users that refer to that lint to e.g. allow it, instead of a more informative warning.
This update should fix that for nightly users.
r? @oli-obk
Prevent String::retain from creating non-utf8 strings when abusing panic
Fixes#78498
The idea is the same as `Vec::drain`, set the len to 0 so that nobody can observe the broken invariant if it escapes the function (in this case if `f` panics)
