Rollup of 14 pull requests

Successful merges:

 - #159307 (Improve cross-namespace name diagnostics)
 - #159543 (Remove extra semicolons in parsing item lists)
 - #157270 (ergonomic_clones_dotuse_capture_by_ref: Capture upvar by ref for `.use` in non-move closures)
 - #158496 (Move `check_rustc_pub_transparent` into the attribute parser)
 - #158547 (Move `std::io::buffered` to `alloc::io`)
 - #158808 (Filter host libstdc++ ABI flag in rustc_llvm cross builds)
 - #159362 (Add regression test for #120328)
 - #159472 (Support creating float constants in rustc_public mir)
 - #159505 (make rustdoc::bare_urls strip trailing periods from url)
 - #159568 (Suggest close compiler options)
 - #159578 (Extract coroutine closure helper functions)
 - #159601 (Make `TokenTreeCursor` private)
 - #159613 (Set the rustc lib path for unstable-book-gen)
 - #159616 (Clarify the comment about stage1/stage2 discrepancy in input-stats test)

Rollup merge of #158808 - chitao1234:fix-rustc-llvm-cross-libstdcxx-abi, r=cuviper

Filter host libstdc++ ABI flag in rustc_llvm cross builds

`compiler/rustc_llvm/build.rs` invokes `llvm-config` for the build host machine in cross compilation scenarios. In particular, the normal LLVM configuration on Linux sets `_GLIBCXX_USE_CXX11_ABI=1` and those flags would then pollute C++ wrapper objects being compiled for the target.

This patch makes `rustc_llvm` avoid propagating that macro when cross-compiling. This follows the existing pattern in `rustc_llvm/build.rs`, which already treats parts of cross `llvm-config` output as host-specific by filtering `-m*` flags and rewriting include paths. Although I think the more appropriate approach is to use a separate target LLVM C++ flags setting.

This currently affects Haiku rustc cross-compilation from Linux hosts. The Haiku target currently uses the old libstdc++ string ABI by default and that creates an ABI mismatch. I currently work around this locally by setting environment variable `CXXFLAGS_x86_64_unknown_haiku=-D_GLIBCXX_USE_CXX11_ABI=0`.

Rollup of 14 pull requests

Successful merges:

 - rust-lang/rust#159307 (Improve cross-namespace name diagnostics)
 - rust-lang/rust#159543 (Remove extra semicolons in parsing item lists)
 - rust-lang/rust#157270 (ergonomic_clones_dotuse_capture_by_ref: Capture upvar by ref for `.use` in non-move closures)
 - rust-lang/rust#158496 (Move `check_rustc_pub_transparent` into the attribute parser)
 - rust-lang/rust#158547 (Move `std::io::buffered` to `alloc::io`)
 - rust-lang/rust#158808 (Filter host libstdc++ ABI flag in rustc_llvm cross builds)
 - rust-lang/rust#159362 (Add regression test for rust-lang/rust#120328)
 - rust-lang/rust#159472 (Support creating float constants in rustc_public mir)
 - rust-lang/rust#159505 (make rustdoc::bare_urls strip trailing periods from url)
 - rust-lang/rust#159568 (Suggest close compiler options)
 - rust-lang/rust#159578 (Extract coroutine closure helper functions)
 - rust-lang/rust#159601 (Make `TokenTreeCursor` private)
 - rust-lang/rust#159613 (Set the rustc lib path for unstable-book-gen)
 - rust-lang/rust#159616 (Clarify the comment about stage1/stage2 discrepancy in input-stats test)