Support memcpy/memmove with differing src/dst alignment
If LLVM 7 is used, generate memcpy/memmove with differing src/dst alignment. I've added new FFI functions to construct these through the builder API, which is more convenient than dealing with differing intrinsic signatures depending on the LLVM version.
Fixes#49740.
(The commit prior to this actual passes our test suite, "thanks"
to #55695. But since I am aware of that bug, I took advantage of it
in choosing how to order my commit series...)
Currently Cargo will always capture the output of rustc meaning that
rustc is never hooked up to a tty. To retain colors Cargo uses the
`fwdansi` crate to ensure that ansi color codes are translated to
windows terminal methods (and ansi codes otherwise just go their natural
route on Unix).
Cargo passes `--color always` to rustc to ensure that using a pipe
doesn't trick it into not emitting colors at all. It turns out, however,
that `--color always` ends up still accidentally using the native shell
api on native windows shells.
The fix here is to instead pass `AlwaysAnsi` to `termcolor` instead of
`Always`, ensuring that when `--color always` is passed to rustc and its
output isn't a terminal, we're always generating ansi colors regardless
of the platform.
Closes#55769
The `wasm32-unknown-emscripten` expects the `rust_eh_personality` symbol to be there, but a cfg checking for `target_arch = "wasm32"` which was meant to remove the symbol from the `wasm32-unknown-unknown` target, didn't check for whether `emscripten` is targeted or not, so the symbol accidentally got filtered out there as well.
Fixes#55276
Rollup of 14 pull requests
Successful merges:
- #55377 (Slight copy-editing for `std::cell::Cell` docs)
- #55441 (Remove unused re import in gdb_rust_pretty_printing)
- #55453 (Choose predicates without inference variables over those with them)
- #55495 (Don't print opt fuel messages to stdout because it breaks Rustbuild)
- #55501 (Make `process_obligations`' computation of `completed` optional.)
- #55510 (Fix feature gate only being checked on first repr attr.)
- #55609 (Run name-anon-globals after LTO passes as well)
- #55645 (do not print wrapping ranges like normal ranges in validity diagnostics)
- #55688 (Standardised names and location of ui issue tests)
- #55692 (-C remark: fix incorrect warning about requiring "--debuginfo" instead of "-C debuginfo=n")
- #55702 (Add `aarch64-pc-windows-msvc` to deployed targets)
- #55728 (Update lldb)
- #55730 (Use trait impl method span when type param mismatch is due to impl Trait)
- #55734 (refactor: use shorthand fields)
This is a (much) more constrained version of #54772 that also aims at
improving the situation in #34681. It removes any font specifications
that are not the "official" rustdoc font, and instead relies on the
browser to provide the fallback font if the official on is not
available. On Linux systems, this is particularly important, as fonts
like Helvetica, Arial, and Times often look pretty bad since they're
pulled from extracted MS fonts. A specification like `serif` or
`sans-serif` lets the browser instead choose a good font.
This commit filters out locals that have never been initialized for
consideration in the `unused_mut` lint.
This is intended to detect when the statement that would have
initialized the local was removed as unreachable code. In these cases,
we would not want to lint. This is the same behaviour as the AST borrow
checker.
This is achieved by taking advantage of an existing pass over the MIR
for the `unused_mut` lint and creating a set of those locals that were
never initialized.
