A variety of improvements to the codegen backends
Some are just general improvements to cg_ssa or cg_llvm, while others will make it slightly easier to use cg_ssa in cg_clif in the future.
Emit warning while outputs is not exe and prints linkage info
cc #137384
```bash
$ rustc +stage1 /dev/null --print native-static-libs --crate-type staticlib --emit metadata
warning: skipping link step due to conflict: cannot output linkage information without emitting executable
note: consider emitting executable to print link information
warning: 1 warning emitted
```
There is no safety contract and I don't think any of them can actually
cause UB in more ways than passing malicious source code to rustc can.
While LtoModuleCodegen::optimize says that the returned ModuleCodegen
points into the LTO module, the LTO module has already been dropped by
the time this function returns, so if the returned ModuleCodegen indeed
points into the LTO module, we would have seen crashes on every LTO
compilation, which we don't. As such the comment is outdated.
Improve intrinsic handling in cg_ssa
* Move all intrinsic handling code to the start of `codegen_call_terminator`.
* Push some intrinsic handling code into `codegen_intrinsic_call`.
* Don't depend on FnAbi for intrinsics.
Intrinsics are not real functions and as such don't have any calling
convention. Trying to compute a calling convention for an intrinsic
anyway is a nonsensical operation.
- Rename `USED` to `USED_COMPILER` to better reflect its behavior.
- Reorder some items to group the used and allocator flags together
- Renumber them without gaps
Use the fn_span when emitting function calls for better debug info.
This especially improves the developer experience for long chains of function calls that span multiple lines, which is common with builder patterns, chains of iterator/future combinators, etc.
try-job: armhf-gnu
try-job: test-various
try-job: x86_64-msvc-1
try-job: arm-android
r? `@jieyouxu`
This especially improves the developer experience for long chains
of function calls that span multiple lines, which is common with
builder patterns, chains of iterator/future combinators, etc.
make `rustc_attr_parsing` less dominant in the rustc crate graph
It has/had a glob re-export of `rustc_attr_data_structures`, which is a crate much lower in the graph, and a lot of crates were using it *just* (or *mostly*) for that re-export, while they can rely on `rustc_attr_data_structures` directly.
Previous graph:

Graph with this PR:

The first commit keeps the re-export, and just changes the dependency if possible. The second commit is the "breaking change" which removes the re-export, and "explicitly" adds the `rustc_attr_data_structures` dependency where needed. It also switches over some src/tools/*.
The second commit is actually a lot more involved than I expected. Please let me know if it's a better idea to back it out and just keep the first commit.
bump windows crate for compiler,bootstrap and tools
This dedupes crate versions. For `x86_64-pc-windows-msvc` stage1 cuts few kb from `rustc_driver.dll`, nice.
turn lld warning on old gccs into info log
As discussed in #140964 and IRL, this PR switches the spammy warning shown unconditionally when an old gcc doesn't support `-fuse-ld=lld` and we retry linking without it, to an info debug log so we don't lose it.
r? `@Mark-Simulacrum`
Fixes#140964
Unfortunately, multiple people are reporting linker warnings related to
`__rust_no_alloc_shim_is_unstable` after this change. The solution isn't
quite clear yet, let's revert to green for now, and try a reland with a
determined solution for `__rust_no_alloc_shim_is_unstable`.
This reverts commit c8b7f32434, reversing
changes made to 667247db71.
Stage0 bootstrap update
This PR [follows the release process](https://forge.rust-lang.org/release/process.html#master-bootstrap-update-tuesday) to update the stage0 compiler.
The only thing of note is 58651d1b31, which was flagged by clippy as a correctness fix. I think allowing that lint in our case makes sense, but it's worth to have a second pair of eyes on it.
r? `@Mark-Simulacrum`
remove 'unordered' atomic intrinsics
As their doc comment already indicates, these operations do not currently have a place in our memory model. The intrinsics were introduced to support a hack in compiler-builtins, but that hack recently got removed (see https://github.com/rust-lang/compiler-builtins/issues/788).