we never reach the code checking for this flag while the
flag is enabled, so it does not change the behavior
of the code.

So they match the order in the `Decoder` trait.

In rust-lang#110927 the encode/decode methods for `i8`, `char`, `bool`, and `str`
were made inherent. This commit removes some unnecessary implementations
of these methods that were missed in that PR.

`MemEncoder` was recently removed, leaving `FileEncoder` as the only
encoder. So this prefix is no longer needed, and `write_leb128!` matches
the existing `read_leb128!`.

Make them generate the entire function, not just the function body.

This is needed to build libunwind for LLVM 16:
https://discourse.llvm.org/t/runtimes-removed-support-for-llvm-enable-projects-in-libcxx-libcxxabi-and-libunwind/65707

Doesn't work: with this, running `python3 x.py dist` produces a tar
archive that still doesn't contain the runtimes subdirectory?

Because it then just has to be filtered out.

This change makes this test more like these other tests:
- tests/ui/treat-err-as-bug/err.rs
- tests/ui/treat-err-as-bug/delay_span_bug.rs
- tests/ui/mir/validate/storage-live.rs
- tests/ui/associated-inherent-types/bugs/ice-substitution.rs
- tests/ui/layout/valid_range_oob.rs

This test is supposed to ensure that full backtraces are used for ICEs.
But it doesn't actually do that -- the filtering done cannot distinguish
between a full backtrace versus a short backtrace.

So this commit changes the filtering to preserve the existence of
`__rust_{begin,end}_short_backtrace` markers, which only appear in full
backtraces. This change means the test now tests what it is supposed to
test.

Also, the existing filtering included a rule that excluded any line
starting with two spaces. This was too strong because it filtered out
some parts of the error message. (This was not a showstopper). It was
also not strong enough because it didn't work with three digit stack
frame numbers, which just started seeing after upgrading my Ubuntu
distro to 23.04 machine (this *was* a showstopper).

So the commit replaces that rule with two more precise rules, one for
lines with stack frame numbers, and one for "at ..." lines.

Previously, this was only passed to miri and compiletest. Extended it to
all other tests and binaries as well.

avoid duplicating TLS state between test std and realstd

This basically re-lands rust-lang#100201 and rust-lang#106638, which got reverted by rust-lang#110861. This works around 2 Miri limitations:
- Miri doesn't support the magic linker section that our Windows TLS support relies on, and instead knows where in std to find the symbol that stores the thread callback.
- For macOS, Miri only supports at most one destructor to be registered per thread.

The 2nd would not be very hard to fix (though the intended destructor order is unclear); the first would be a lot of work to fix. Neither of these is a problem for regular Rust code, but in the std test suite we have essentially 2 copies of the std code and then these both become issues. To avoid that we have the std test crate import the TLS code from the real std instead of having its own copy.

r? ``````@m-ou-se``````

…iser

Reject borrows of projections in ConstProp.

Fixes rust-lang#110947

Fix problems with backtraces in two ui tests.

`default-backtrace-ice.rs` started started failing for me recently,
because on my Ubuntu 23.04 system there are 100 stack frames, and the
current stack filtering pattern doesn't match on a stack frame with a
three digit number.

`issue-86800.rs` can also be improved, backtrace-wise.

r? `@Nilstrieb`

cleanup nll generalizer

followup to rust-lang#108861

…anups, r=cjgillot

Still more encoder cleanups

r? ``@cjgillot``

bootstrap: add llvm-project/runtimes to the sources

This is needed to build libunwind for LLVM 16:
https://discourse.llvm.org/t/runtimes-removed-support-for-llvm-enable-projects-in-libcxx-libcxxabi-and-libunwind/65707

Zulip thread: https://rust-lang.zulipchat.com/#narrow/stream/187780-t-compiler.2Fwg-llvm/topic/missing.20llvm-project.2Fruntimes.20in.20beta.20srcs

Checked by running `x.py dist` and verifying the produced source archive (build/dist/rustc-1.71.0-dev-src.tar.gz) contains the new directory.

Fixup "since" dates for `array_tuple_conv` feature

Fixes a mistake from rust-lang#97594

Use `free-args` consistently in bootstrap

Previously, this was only passed to miri and compiletest. Extended it to all other tests and binaries as well.

cc https://rust-lang.zulipchat.com/#narrow/stream/326414-t-infra.2Fbootstrap/topic/Running.20a.20single.20doctest

r? `@clubby789`