check wf before const-evaluating

[zedddie]

(todo: better pr description)
I am not sure whether this is the way it should be done or not, and if it is I will need to rewrite few comments.

This also changed some coherence related stuff with consts (dont know if its an improvement or regression though), ci will fail on them

r? BoxyUwU

[rustbot]

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[rust-log-analyzer]

The job aarch64-gnu-llvm-21-1 failed! Check out the build log: (web) (plain enhanced) (plain)

Click to see the possible cause of the failure (guessed by this bot)

---- [ui] tests/ui/const-generics/generic_const_exprs/issue-73899.rs stdout ----

error: test compilation failed although it shouldn't!
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/const-generics/generic_const_exprs/issue-73899.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "-O" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "-C" "prefer-dynamic" "-o" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/const-generics/generic_const_exprs/issue-73899/a" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error[E0119]: conflicting implementations of trait `FooImpl<{ 0u8 == 0u8 }>` for type `[(); 0]`
##[error]  --> /checkout/tests/ui/const-generics/generic_const_exprs/issue-73899.rs:13:1
   |
LL | impl FooImpl<{ 0u8 == 0u8 }> for [(); 0] {}
   | ---------------------------------------- first implementation here
LL |
LL | impl<const N: usize> FooImpl<{ 0u8 != 0u8 }> for [(); N] {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `[(); 0]`

error: aborting due to 1 previous error

For more information about this error, try `rustc --explain E0119`.
------------------------------------------

---- [ui] tests/ui/const-generics/generic_const_exprs/issue-73899.rs stdout end ----
---- [ui] tests/ui/const-generics/overlapping_impls.rs stdout ----

error: test compilation failed although it shouldn't!
status: exit status: 1
command: env -u RUSTC_LOG_COLOR RUSTC_ICE="0" RUST_BACKTRACE="short" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/const-generics/overlapping_impls.rs" "-Zthreads=1" "-Zsimulate-remapped-rust-src-base=/rustc/FAKE_PREFIX" "-Ztranslate-remapped-path-to-local-path=no" "-Z" "ignore-directory-in-diagnostics-source-blocks=/cargo" "-Z" "ignore-directory-in-diagnostics-source-blocks=/checkout/vendor" "--sysroot" "/checkout/obj/build/aarch64-unknown-linux-gnu/stage2" "--target=aarch64-unknown-linux-gnu" "--check-cfg" "cfg(test,FALSE)" "--error-format" "json" "--json" "future-incompat" "-Ccodegen-units=1" "-Zui-testing" "-Zdeduplicate-diagnostics=no" "-Zwrite-long-types-to-disk=no" "-Cstrip=debuginfo" "--emit" "metadata" "-C" "prefer-dynamic" "--out-dir" "/checkout/obj/build/aarch64-unknown-linux-gnu/test/ui/const-generics/overlapping_impls" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/aarch64-unknown-linux-gnu/native/rust-test-helpers"
stdout: none
--- stderr -------------------------------
error[E0119]: conflicting implementations of trait `Bar` for type `Foo2<{ Protocol::Variant1 }, _>`
##[error]  --> /checkout/tests/ui/const-generics/overlapping_impls.rs:35:1
   |
LL | impl<T> Bar for Foo2<{ Protocol::Variant1 }, T> {}
   | ----------------------------------------------- first implementation here
LL | impl<T> Bar for Foo2<{ Protocol::Variant2 }, T> {}
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `Foo2<{ Protocol::Variant1 }, _>`

error[E0592]: duplicate definitions with name `foo`
##[error]  --> /checkout/tests/ui/const-generics/overlapping_impls.rs:14:5
   |
LL |     pub fn foo() {}