rewrite incr-prev-body-beyond-eof in rmake

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -79,7 +79,6 @@ run-make/inaccessible-temp-dir/Makefile
 run-make/include_bytes_deps/Makefile
 run-make/incr-add-rust-src-component/Makefile
 run-make/incr-foreign-head-span/Makefile
-run-make/incr-prev-body-beyond-eof/Makefile
 run-make/incremental-debugger-visualizer/Makefile
 run-make/incremental-session-fail/Makefile
 run-make/inline-always-many-cgu/Makefile

tests/run-make/incr-prev-body-beyond-eof/rmake.rs

@@ -0,0 +1,32 @@
+// After modifying the span of a function, if the length of
+// the span remained the same but the end line number became different,
+// this would cause an internal compiler error (ICE), fixed in #76256.
+
+// This test compiles main.rs twice, first with end line 16 and
+// then with end line 12. If compilation is successful, the end line
+// was hashed by rustc in addition to the span length, and the fix still
+// works.
+
+// FIXME: Ignore flags temporarily disabled for the test.
+// ignore-none
+// ignore-nvptx64-nvidia-cuda
+
+use run_make_support::{rustc, target, tmp_dir};
+use std::fs;
+
+fn main() {
+    fs::create_dir(tmp_dir().join("src"));
+    fs::create_dir(tmp_dir().join("incr"));
+    fs::copy("a.rs", tmp_dir().join("main.rs"));
+    rustc()
+        .incremental(tmp_dir().join("incr"))
+        .input(tmp_dir().join("src/main.rs"))
+        .target(target())
+        .run();
+    fs::copy("b.rs", tmp_dir().join("main.rs"));
+    rustc()
+        .incremental(tmp_dir().join("incr"))
+        .input(tmp_dir().join("src/main.rs"))
+        .target(target())
+        .run();
+}