assumptions_on_binders: Test mixed ambiguous ORs

[Dnreikronos]

Follow up to #162442. Boxy pointed out that one got superseded by #162935, and yeah, once adwin's PR removes propagate_ambiguity there's nothing left for my code change to do. The test still covers a case nothing else does though, so this just moves the test over.

The idea is an OR where one side is an alias outlives with a non-lifetime binder, which ends up ambiguous, and the other side is something we can prove from the root assumptions. That should hold no matter which order the OR is in. I also kept the cases that should still error, an AND where the ambiguous part is still required and an OR where every side is ambiguous. adwin mentioned in #162935 they weren't sure what to do with the non-lifetime binder ambiguity yet, so I think it's nice to have something pinning down how it behaves today.

This depends on both #161988 and #162935, so it'll fail until both land. I tested it locally with adwin's branch plus #161988 merged on top and all of assumptions_on_binders passes. With only #162935 the pass cases fail, since the root still treats every leaf of an OR as required and reports the ambiguous side even when the other side is fine. I'll rebase once they're in.

cc @BoxyUwU

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[rust-log-analyzer]

The job test-x86_64-gnu-gcc 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/assumptions_on_binders/mixed-ambiguous-alias-outlives.rs#pass stdout ----

error in revision `pass`: 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/x86_64-unknown-linux-gnu/stage2/bin/rustc" "/checkout/tests/ui/assumptions_on_binders/mixed-ambiguous-alias-outlives.rs" "-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/x86_64-unknown-linux-gnu/stage2" "-Zcodegen-backend=gcc" "--target=x86_64-unknown-linux-gnu" "--cfg" "pass" "--check-cfg" "cfg(test,FALSE,pass,fail)" "--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/x86_64-unknown-linux-gnu/test/ui/assumptions_on_binders/mixed-ambiguous-alias-outlives.pass" "-Znext-solver=coherence" "-A" "unused" "-W" "unused_attributes" "-A" "internal_features" "-A" "incomplete_features" "-A" "unused_parens" "-A" "unused_braces" "-Crpath" "-Cdebuginfo=0" "-Lnative=/checkout/obj/build/x86_64-unknown-linux-gnu/native/rust-test-helpers" "-Zassumptions-on-binders"
stdout: none
--- stderr -------------------------------
error: unable to satisfy constraints involving placeholders due to unknown implied bounds
##[error]  --> /checkout/tests/ui/assumptions_on_binders/mixed-ambiguous-alias-outlives.rs:21:9
   |

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