do not inline black_box when building for Miri
We cannot do the assembly trick in Miri, but let's at least make sure MIR inlining does not circumvent the black_box.
Also use black_box instead of local optimization barriers in a few const tests.
Add test for checking duplicated branch or-patterns
This adds a regression test for checking `or-patterns` in MIR as shown in #75439.
This doesn't introduce a fix as I'm not sure where it would go(I suspect maybe here: src/librustc_mir_build/build/matches/mod.rs), and I'm not particularly able to fix it.
cc: @lzutao
lint/ty: move fns to avoid abstraction violation
This PR moves `transparent_newtype_field` and `is_zst` to `LateContext` where they are used, rather than being on the `VariantDef` and `TyS` types, hopefully addressing @eddyb's concern [from this comment](https://github.com/rust-lang/rust/pull/74340#discussion_r456534910).
deny(unsafe_op_in_unsafe_fn) in libstd/path.rs
The libstd/path.rs part of #73904 . Wraps the two calls to an unsafe fn Initializer::nop() in an unsafe block.
Wrap recursive predicate evaluation with `ensure_sufficient_stack`
I haven't been able to come up with a minimized test case for #76770,
but this fixes a stack overflow in rustc as well.
As a side effect, we now represent most promoteds as `ConstValue::Scalar` again. This is useful because all implict promoteds are just references anyway and most explicit promoteds are numeric arguments to `asm!` or SIMD instructions.
Upgrade libz-sys to 1.1.2
The current version has warnings that become errors on new versions of clang shipped in XCode:
```
warning: src/zlib/gzlib.c:214:15: error: implicitly declaring library function 'snprintf' with type 'int (char *, unsigned long, const char *, ...)' [-Werror,-Wimplicit-function-declaration]
warning: (void)snprintf(state->path, len + 1, "%s", (const char *)path);
warning: ^
warning: src/zlib/gzlib.c:214:15: note: include the header <stdio.h> or explicitly provide a declaration for 'snprintf'
warning: 1 error generated.
warning: src/zlib/gzwrite.c:428:11: error: implicitly declaring library function 'vsnprintf' with type 'int (char *, unsigned long, const char *, __builtin_va_list)' [-Werror,-Wimplicit-function-declaration
warning: len = vsnprintf(next, state->size, format, va);
warning: ^
warning: src/zlib/gzwrite.c:428:11: note: include the header <stdio.h> or explicitly provide a declaration for 'vsnprintf'
warning: 1 error generated.
```
r? `@Mark-Simulacrum`
/cc `@joshtriplett`
Distribute rustc sources as part of `rustc-dev`
They can be used to provide IDE features when working on rustc plugins/backends/etc without having to locate a separate Rust checkout.
r? `@Mark-Simulacrum`
Dogfood new_uninit and maybe_uninit_slice in rustc_arena
Dogfoods a few cool `MaybeUninit` related features in the compiler's rustc_arena crate.
Split off from #76821
r? `@oli-obk`
Some MIR statements and terminators have an (undocumented...) invariant
that some of their input and outputs must not overlap. This records
conflicts between locals used in these positions.
