Point at all the unnecessary trailing `#`.
Better handle interaction with outer attributes when `;` is missing.

Fix rust-lang#95030.

In rust-lang#96303, I changed the tests not to manage submodules, with the main
goal of avoiding a clone for llvm-project. Unfortunately, there are some tests
which depend on submodules - I didn't notice locally because they were already checked out for me,
and CI doesn't use submodule handling at all. Fresh clones, however, were impacted:
```
failures:

---- builder::tests::defaults::doc_default stdout ----
thread 'main' panicked at 'fs::read_dir(builder.src.join(&relative_path).join("redirects")) failed with No such file or directory (os error 2)', src/bootstrap/doc.rs:232:21
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

---- builder::tests::dist::dist_only_cross_host stdout ----
thread 'main' panicked at 'fs::read_to_string(&toml_file_name) failed with No such file or directory (os error 2)', src/bootstrap/lib.rs:1314:20
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

Try and get the best of both worlds by only checking out the submodules actually used in tests.

set has_thread_local=true for android

It seems that llvm uses emulated tls on android by default since [this commit](https://reviews.llvm.org/D42999). Which uses a `pthread_key` to emulate various tls objects at runtime([code](https://github.com/llvm-mirror/compiler-rt/blob/master/lib/builtins/emutls.c)).

I've built a demo with a custom android target setting `has_thread_local=true` and a slightly modified `std` as what this PR does, and it works fine. The generated function symbol `__emutls_get_address`  would link to an implementation in `libgcc.a` , which is also [required by std](https://github.com/rust-lang/rust/blob/master/library/unwind/build.rs#L18) for now.

By enable `has_thread_local`, we can reduce the number of `pthread_key`s used by rust libraries on android, which are quite limited resources(128 per process). I've been investgating some crashes caused by unable to create more pthread_key in our project with about 80 `pthread_key`s used by rust part.

cc rust-lang#96145  [rust-lang/compiler-builtins#458](rust-lang/compiler-builtins#458)

…rors

Better handle too many `#` recovery in raw str

Point at all the unnecessary trailing `#`.
Better handle interaction with outer attributes when `;` is missing.

Fix rust-lang#95030.

Switch JS code to ES6

Considering it's already quite big, I'll do the remaining files in another PR.

Part of rust-lang#93058.

r? `@notriddle`

…-Simulacrum

Fix running bootstrap tests on a fresh clone

In rust-lang#96303, I changed the tests not to manage submodules, with the main
goal of avoiding a clone for llvm-project. Unfortunately, there are some tests
which depend on submodules - I didn't notice locally because they were already checked out for me,
and CI doesn't use submodule handling at all. Fresh clones, however, were impacted:
```
failures:

---- builder::tests::defaults::doc_default stdout ----
thread 'main' panicked at 'fs::read_dir(builder.src.join(&relative_path).join("redirects")) failed with No such file or directory (os error 2)', src/bootstrap/doc.rs:232:21
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

---- builder::tests::dist::dist_only_cross_host stdout ----
thread 'main' panicked at 'fs::read_to_string(&toml_file_name) failed with No such file or directory (os error 2)', src/bootstrap/lib.rs:1314:20
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

Try and get the best of both worlds by only checking out the submodules actually used in tests.