Make copy/copy_nonoverlapping fn's again

[pnkfelix]

Make copy/copy_nonoverlapping fn's again, rather than intrinsics.

This a short-term change to address issue #84297.

It effectively reverts PRs #81167 #81238 (and part of #82967), #83091, and parts of #79684.

[rust-highfive]

Some changes occurred in src/tools/clippy.

cc @rust-lang/clippy

[rust-highfive]

r? @yaahc

(rust-highfive has picked a reviewer for you, use r? to override)

[pnkfelix]

oh wait I need a regression test too. :)

[pnkfelix]

r? @Mark-Simulacrum

[pnkfelix]

The job mingw-check failed! Check out the build log: (web) (plain)
Click to see the possible cause of the failure (guessed by this bot)

configure: rust.channel         := nightly
configure: rust.debug-assertions := True
configure: llvm.assertions      := True
configure: dist.missing-tools   := True
configure: build.configure-args := ['--enable-sccache', '--disable-manage-submodu ...
configure: writing `config.toml` in current directory
configure: 
configure: run `python /checkout/x.py --help`
configure: 
---
    Checking rand v0.7.3
    Checking alloc v0.0.0 (/checkout/library/alloc)
    Checking std v0.0.0 (/checkout/library/std)
    Checking core v0.0.0 (/checkout/library/core)
error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
   |
   |
60 |             ptr::write(&mut res as *mut _, 42);


error[E0015]: calls in constant functions are limited to constant functions, tuple structs and tuple variants
   |
   |
84 |             (&mut res as *mut i32).write(42);

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0015`.
For more information about this error, try `rustc --explain E0015`.
error: could not compile `core`

To learn more, run the command again with --verbose.
warning: build failed, waiting for other jobs to finish...
error: build failed
command did not execute successfully: "/checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo" "check" "--target" "i686-pc-windows-gnu" "-Zbinary-dep-depinfo" "-j" "16" "--release" "--locked" "--color" "always" "--features" "panic-unwind backtrace compiler-builtins-c" "--manifest-path" "/checkout/library/test/Cargo.toml" "--all-targets" "-p" "test" "-p" "panic_abort" "-p" "alloc" "-p" "core" "-p" "panic_unwind" "-p" "unwind" "-p" "term" "-p" "std" "-p" "proc_macro" "--message-format" "json-render-diagnostics"
failed to run: /checkout/obj/build/bootstrap/debug/bootstrap check --target=i686-pc-windows-gnu --host=i686-pc-windows-gnu --all-targets
Build completed unsuccessfully in 0:00:31

weird, my local build+tests passed. Looking now.

Update: Oh, my local build driver script only runs x.py test on stuff under src/test/. Heh, whoops.

[Mark-Simulacrum]

@bors r+ p=1

Mostly just reverting some stuff, including unstable const-fn-ing, but seems good.

[bors]

📌 Commit f08f933 has been approved by Mark-Simulacrum

[bors]

⌛ Testing commit f08f933 with merge 957453fc62205d24f9c5e331c4b68fe802e83797...

[bors]

💔 Test failed - checks-actions

[apiraino]

Beta backport accepted as per compiler team on Zulip

@rustbot label +beta-accepted

[Mark-Simulacrum]

beta backported in #86203

[rylev]

@pnkfelix @Mark-Simulacrum This change led to some moderate performance regressions. I imagine performance regressions are somewhat expected going from intrinsics to function calls as it seems LLVM might have more to process now. A quick look at where the regressions are happening shows it to be mostly in codegen. Any thoughts?

[Mark-Simulacrum]

This was a stopgap measure to fix regressions; it should be fixable in the long run. I don't think it makes sense to prioritize the work too much though.