rewrite and rename issue-83112-incr-test-moved-file to rmake

Author: Oneirical

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -62,7 +62,6 @@ run-make/issue-36710/Makefile
 run-make/issue-47551/Makefile
 run-make/issue-69368/Makefile
 run-make/issue-83045/Makefile
-run-make/issue-83112-incr-test-moved-file/Makefile
 run-make/issue-84395-lto-embed-bitcode/Makefile
 run-make/issue-85019-moved-src-dir/Makefile
 run-make/issue-85401-static-mir/Makefile

tests/run-make/issue-83112-incr-test-moved-file/main.rs renamed to tests/run-make/incr-test-moved-file/main.rs

@@ -0,0 +1,27 @@
+// The generated test harness code contains spans with a dummy location,
+// but a non-dummy SyntaxContext. Previously, the incremental cache was encoding
+// these spans as a full span (with a source file index), instead of skipping
+// the encoding of the location information. If the file gest moved, the hash
+// of the span will be unchanged (since it has a dummy location), so the incr
+// cache would end up try to load a non-existent file using the previously
+// enccoded source file id.
+// This test reproduces the steps that used to trigger this bug, and checks
+// for successful compilation.
+// See https://github.com/rust-lang/rust/issues/83112
+
+//@ ignore-none
+// Reason: no-std is not supported
+//@ ignore-nvptx64-nvidia-cuda
+// FIXME: can't find crate for 'std'
+
+use run_make_support::{fs_wrapper, rust_lib_name, rustc};
+
+fn main() {
+    fs_wrapper::create_dir("incr");
+    fs_wrapper::create_dir("src");
+    fs_wrapper::create_dir("src/mydir");
+    fs_wrapper::copy("main.rs", "src/main.rs");
+    rustc().input("src/main.rs").incremental("incr").arg("--test").run();
+    fs_wrapper::rename("src/main.rs", "src/mydir/main.rs");
+    rustc().input("src/mydir/main.rs").incremental("incr").arg("--test").run();
+}