Deprecate several flags in rustdoc
Part of #44136
cc @rust-lang/dev-tools @rust-lang/docs
This is a very basic PR to start deprecating some flags; `rustdoc` doesn't really have fancy output options like `rustc` does, so I went with `eprintln!`. Happy to change it if people feel that's not appropriate.
Also, I have no idea if we can or should write tests here, so I didn't try. If someone feels strongly about it, then let's do it, but given that the only outcome here is a side effect...
rustbuild: Support specifying archiver and linker explicitly
With this patch `x.py test` passes without toolchain being in `PATH` if `cc`, `cxx`, `ar`, `linker` and `gdb` are specified in `config.toml` (except for a few `run-make` tests using `nm`).
Fixes https://github.com/rust-lang/rust/issues/41821
r? @Mark-Simulacrum
some low-hanging rustdoc optimizations
There were a few discussions earlier today in #rust-internals about the syscall usage and overall performance of rustdoc. This PR is intended to pick some low-hanging fruit and try to rein in some of the performance issues of rustdoc.
Add x86_64-unknown-linux-gnux32 target
This adds X32 ABI support for Linux on X86_64. Let's package and dist it so we can star testing libc, libstd, etc.
Fixes https://github.com/rust-lang/rfcs/issues/1339
doc-test: In Markdown tests, Use all of `<h1>` to `<h6>` as the test name
This mainly simplifies debugging error index tests, as the error codes are `<h2>`s in the huge document containing all codes.
let rustdoc print the crate version into docs
This PR adds a new unstable flag to rustdoc, `--crate-version`, which when present will add a new entry to the sidebar of the root module, printing the given version number:

Closes#24336
(The WIP status is because i don't want to merge this until i can get the std docs to use it, which i need help from rustbuild people to make sure i get right.)
Remove support for the PNaCl target (le32-unknown-nacl)
This removes support for the `le32-unknown-nacl` target which is currently supported by rustc on tier 3. Despite the "nacl" in the name, the target doesn't output native code (x86, ARM, MIPS), instead it outputs binaries in the PNaCl format.
There are two reasons for the removal:
* Google [has announced](https://blog.chromium.org/2017/05/goodbye-pnacl-hello-webassembly.html) deprecation of the PNaCl format. The suggestion is to migrate to wasm. Happens we already have a wasm backend!
* Our PNaCl LLVM backend is provided by the fastcomp patch set that the LLVM fork used by rustc contains in addition to vanilla LLVM (`src/llvm/lib/Target/JSBackend/NaCl`). Upstream LLVM doesn't have PNaCl support. Removing PNaCl support will enable us to move away from fastcomp (#44006) and have a lighter set of patches on top of upstream LLVM inside our LLVM fork. This will help distribution packagers of Rust.
Fixes#42420
Initial support for `..=` syntax
#28237
This PR adds `..=` as a synonym for `...` in patterns and expressions.
Since `...` in expressions was never stable, we now issue a warning.
cc @durka
r? @aturon
put empty generic lists behind a pointer
This reduces the size of hir::Expr from 128 to 88 bytes (!) and shaves
200MB out of #36799.
This is a performance-sensitive PR so please don't roll it up.
r? @eddyb
Add ..= to the parser
Add ..= to libproc_macro
Add ..= to ICH
Highlight ..= in rustdoc
Update impl Debug for RangeInclusive to ..=
Replace `...` to `..=` in range docs
Make the dotdoteq warning point to the ...
Add warning for ... in expressions
Updated more tests to the ..= syntax
Updated even more tests to the ..= syntax
Updated the inclusive_range entry in unstable book