Refine run-make test ignores due to unpredictable i686-pc-windows-gnu unwind mechanism

Author: jieyouxu

tests/run-make/dump-ice-to-disk/rmake.rs

@@ -17,14 +17,14 @@
 //!
 //! # Test history
 //!
-//! - The previous rmake.rs iteration of this test was flakey for unknown reason on `i686-mingw`
-//!   *specifically*, so assertion failures in this test was made extremely verbose to help
-//!   diagnose why the ICE messages was different *specifically* on `i686-mingw`.
-//! - An attempt is made to re-enable this test on `i686-mingw` (by removing `ignore-windows`). If
-//!   this test is still flakey, please restore the `ignore-windows` directive.
-
-//@ ignore-windows
-//FIXME(#128911): still flakey on i686-mingw.
+//! The previous rmake.rs iteration of this test was flaky for unknown reason on
+//! `i686-pc-windows-gnu` *specifically*, so assertion failures in this test was made extremely
+//! verbose to help diagnose why the ICE messages was different. It appears that backtraces on
+//! `i686-pc-windows-gnu` specifically are quite unpredictable in how many backtrace frames are
+//! involved.
+
+//@ ignore-cross-compile (exercising ICE dump on host)
+//@ ignore-i686-pc-windows-gnu (unwind mechanism produces unpredictable backtraces)
 
 use std::cell::OnceCell;
 use std::path::{Path, PathBuf};

tests/run-make/unstable-feature-usage-metrics-incremental/rmake.rs

@@ -7,12 +7,11 @@
 //!
 //! # Test history
 //!
-//! - forked from dump-ice-to-disk test, which has flakeyness issues on i686-mingw, I'm assuming
-//! those will be present in this test as well on the same platform
+//! - Forked from `dump-ice-to-disk` test, which previously had backtrace unpredictability on
+//! `i686-pc-windows-gnu`.
 
-//@ needs-target-std
-//@ ignore-windows
-//FIXME(#128911): still flakey on i686-mingw.
+//@ ignore-cross-compile (exercises metrics incremental on host)
+//@ ignore-i686-pc-windows-gnu (unwind mechanism produces unpredictable backtraces)
 
 use std::path::{Path, PathBuf};
 

tests/run-make/unstable-feature-usage-metrics/rmake.rs

@@ -7,12 +7,10 @@
 //!
 //! # Test history
 //!
-//! - forked from dump-ice-to-disk test, which has flakeyness issues on i686-mingw, I'm assuming
-//! those will be present in this test as well on the same platform
+//! - Forked from `dump-ice-to-disk` test, where `i686-pc-windows-gnu` has unpredictable backtraces.
 
-//@ needs-target-std
-//@ ignore-windows
-//FIXME(#128911): still flakey on i686-mingw.
+//@ ignore-cross-compile (exercises metrics dump on host)
+//@ ignore-i686-pc-windows-gnu (unwind mechanism produces unpredictable backtraces)
 
 use std::path::{Path, PathBuf};