[MIR] Temporary hack for 32959

Gets rid of the warning. This is more elegant that I thought it would be, actually.

r? @nikomatsakis

cc #32959

Move auxiliary directories to live with the tests

This is a step for enabling testing of cross-crate incremental compilation. The idea is that instead of having a central auxiliary directory, when you have a `// aux-build:foo.rs` annotation in the test `run-pass/bar.rs`, it will look in (e.g.) `run-pass/aux/foo.rs`. In general, it looks for an `aux` directory in the same directory as the test. We also ignore the `aux` directories when enumerating the set of tests.

As part of this PR, also refactor `runtest.rs` to use methods on a context, which means we can stop passing around context everywhere.

r? @alexcrichton

For legacy reasons (presumably), Windows does not permit files name aux.

Instead of finding aux-build files in `auxiliary`, we now search for an
`aux` directory relative to the test. So if your test is
`compile-fail/foo.rs`, we would look in `compile-fail/aux`.  Similarly,
we ignore the `aux` directory when searching for tets.

Also, promote the for loop iterating over revisions out into the
top-level method, whereas before it was pushed down instead each test's
method. Not entirely clear that this was the right call.

mk: Try to fix nightlies again

Looks like the real bug on nightlies is that the `llvm-pass` run-make test is
not actually getting the value of `LLVM_CXXFLAGS` correct. Namely, it's blank!
Now the only change #33093 which actually affected this is that the argument
`$(LLVM_CXXFLAGS_$(2))` was moved up from a makefile rule into the definition of
a variable. Sounds innocuous?

Turns out the variable this was moved into is defined with `:=`, which means
that it's not recursively expanded, which basically means that it's expanded
immediately. Unfortunately part of this expansion involves running
`llvm-config`, which doesn't exist at the start of distcheck build!

This didn't show up on the bots because they run `make` *then* `make check`, and
the first step builds llvm-config so the next time `make` is loaded everything
is available. The distcheck bots, however, run just a plain `distcheck` so
`make` doesn't exist ahead of time. You can see this in action where the
distcheck bots start out with a bunch of "llvm-config not found" error messages.

This commit just changes a few variables to be defined with `=` which
essentially means they're lazily expanded. I did not run a full distcheck
locally, but this makes the initial "llvm-config not found" error messages go
away so I suspect that this is the fix.

Closes #33379 (hopefully)

Looks like the real bug on nightlies is that the `llvm-pass` run-make test is
not actually getting the value of `LLVM_CXXFLAGS` correct. Namely, it's blank!
Now the only change #33093 which actually affected this is that the argument
`$(LLVM_CXXFLAGS_$(2))` was moved up from a makefile rule into the definition of
a variable. Sounds innocuous?

Turns out the variable this was moved into is defined with `:=`, which means
that it's not recursively expanded, which basically means that it's expanded
immediately. Unfortunately part of this expansion involves running
`llvm-config`, which doesn't exist at the start of distcheck build!

This didn't show up on the bots because they run `make` *then* `make check`, and
the first step builds llvm-config so the next time `make` is loaded everything
is available. The distcheck bots, however, run just a plain `distcheck` so
`make` doesn't exist ahead of time. You can see this in action where the
distcheck bots start out with a bunch of "llvm-config not found" error messages.

This commit just changes a few variables to be defined with `=` which
essentially means they're lazily expanded. I did not run a full distcheck
locally, but this makes the initial "llvm-config not found" error messages go
away so I suspect that this is the fix.

Closes #33379

debuginfo: Fix regression in namespace handling for struct types.

Fixes a small regression that has been introduced in recent refactorings.

Fixes #33193

r? @EddyB

Short-cut `T: Sized` trait selection for ADTs

Basically avoids all nested obligations when checking whether an ADT is sized - this speeds up typeck by ~15%

The refactoring fixed #32963, but I also want to make `Copy` not object-safe (will commit that soon).

Fixes #33201

r? @nikomatsakis

rand: don't block before random pool is initialized

If we attempt a read with getrandom() on Linux the syscall can block
before the random pool is initialized unless the GRND_NONBLOCK flag is
passed. This flag causes getrandom() to instead return EAGAIN while the
pool is uninitialized. To avoid downstream users of crate or std
functionality that have no ability to avoid this blocking behavior this
change causes Rust to read bytes from /dev/urandom while getrandom()
would block and once getrandom() is available to use that. Fixes #32953.
Signed-off-by: NDoug Goldstein <cardoe@cardoe.com>

Panic on overflow in `Duration::new` constructor

Panicking on overflow is also done for `+`, and it replaces the
currently incorrect overflow behavior of wrapping around, which does not
make sense for `Duration`s.

Distribute both rust-lldb and rust-gdb everywhere

Both debuggers are viable in some capacity on all tier-1 platforms,
and people often ask for rust-lldb on Linux or rust-gdb on OS X.

r? @michaelwoerister

I'm still testing locally, but this *looks* like the right thing to change.

Both debuggers are viable in some capacity on all tier-1 platforms,
and people often ask for rust-lldb on Linux or rust-gdb on OS X.

Add `as_mut` methods to the `std::cell` structs

This is safe since the borrow checking ensures that we have the only
mutable reference to the struct, thus we can safely borrow its interior.

This is safe since the borrow checker ensures that we have the only
mutable reference to the struct, thus we can safely borrow its interior.

Tracking issue is #33444.

Add `Default` implementation for `&CStr`, `CString`, `Path`

Add more aliases for Unicode confusable chars

Building upon #29837, this PR:

* added aliases for space characters,
* distinguished square brackets from parens, and
* added common CJK punctuation characters as aliases.

This will especially help CJK users who may have forgotten to switch off IME when coding.

Implement negation for wrapping numerals.

Fixes #33037

mk: Pass CFLAGS for target, not host

This changes the CFLAGS and related variables passed to compiletest to be passed
for the target, not the host, so we can correctly test 32-bit cross compiles on
64-bit host machines.

Hopefuly fixes #33379