Add regression test for issue #147146 ( ICE)

[ManojJiSharma]

Add regression test for issue #147146 (ICE)

This PR adds a minimal UI test reproducing the ICE triggered by using typeof in an impl:
impl typeof(|| {}) {}

The compiler currently panics with an internal compiler error (ICE) when compiling this code.

This test ensures that future fixes to the compiler can be validated against this specific scenario.

Note: This PR does not fix the ICE itself; it only provides a regression test.

References: rust-lang#147146

[rustbot]

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[rustbot]

⚠️ Warning ⚠️

• There are issue links (such as #123) in the commit messages of the following commits.
  Please move them to the PR description, to avoid spamming the issues with references to the commit, and so this bot can automatically canonicalize them to avoid issues with subtree.
  • f6f13f2

[rust-log-analyzer]

The job tidy failed! Check out the build log: (web) (plain enhanced) (plain)

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

[TIMING:end] tool::Tidy { compiler: Compiler { stage: 0, host: x86_64-unknown-linux-gnu, forced_compiler: false }, target: x86_64-unknown-linux-gnu } -- 0.000
fmt check
fmt: checked 6433 files
tidy check
tidy [ui_tests (tests)]: ui tests should be added under meaningful subdirectories: `/checkout/tests/ui/typeof-reserved-ice.rs`
tidy [ui_tests (tests)]: FAIL
tidy [rustdoc_json (src)]: `rustdoc-json-types` modified, checking format version
tidy: Skipping binary file check, read-only filesystem
removing old virtual environment
creating virtual environment at '/checkout/obj/build/venv' using 'python3.10' and 'venv'
creating virtual environment at '/checkout/obj/build/venv' using 'python3.10' and 'virtualenv'
---
info: ES-Check: there were no ES version matching errors!  🎉
typechecking javascript files
tidy: The following check failed: ui_tests (tests)
Bootstrap failed while executing `test src/tools/tidy tidyselftest --extra-checks=py,cpp,js,spellcheck`
Command `/checkout/obj/build/x86_64-unknown-linux-gnu/stage1-tools-bin/rust-tidy /checkout /checkout/obj/build/x86_64-unknown-linux-gnu/stage0/bin/cargo /checkout/obj/build 4 /node/bin/npm --extra-checks=py,cpp,js,spellcheck` failed with exit code 1
Created at: src/bootstrap/src/core/build_steps/tool.rs:1549:23
Executed at: src/bootstrap/src/core/build_steps/test.rs:1280:29

Command has failed. Rerun with -v to see more details.
Build completed unsuccessfully in 0:03:18
  local time: Mon Sep 29 17:48:09 UTC 2025
  network time: Mon, 29 Sep 2025 17:48:09 GMT
##[error]Process completed with exit code 1.
Post job cleanup.

[Kivooeo]

Hi, thanks for your pull request

To get the CI checks to pass, could you please move your test file into a subdirectory under tests/ui/? Our test suite requires that all ui tests be organized in subdirectories rather than placed directly at the root level

Let me know if you have any questions!

[jieyouxu]

Problem: this is outdated syntax

[jieyouxu]

Question: what's the point of this regression test...? This test cannot possibly pass if the ICE isn't fixed

[jieyouxu]

I'm going to close this PR because this regression test should just be included in the PR that actually fixes the ICE. Thanks for the interest.