Update Ruby repo revision

The upstream made some changes to the root-scanning functions, notably,

-   Introduced yjit roots.
-   Seperated root-scanning into the GC-implementation-agnostic
    rb_gc_mark_roots in gc.c and the GC-implementation-specific
    mark_roots in gc/default.c.

In the `ruby` repo, we reorder the root-scanning functions in the upcall
table so that the general functions come before the
implementation-specific functions.  Also added yjit roots as one upcall,
although its implementation is a no-op if yjit is not enabled.

mmtk/Cargo.toml

@@ -12,7 +12,7 @@ edition = "2021"
 # Metadata for the Ruby repository
 [package.metadata.ci-repos.ruby]
 repo = "mmtk/ruby" # This is used by actions/checkout, so the format is "owner/repo", not URL.
-rev = "1c4102e7bcee03f66ca72f916cde0d2bd7a8638b"
+rev = "a55df63fcc186880f2262ab7e54b442f2637ff2b"
 
 [lib]
 name = "mmtk_ruby"

mmtk/src/abi.rs

@@ -356,9 +356,10 @@ pub struct RubyUpcalls {
         data: *mut libc::c_void,
     ),
     pub scan_vm_roots: extern "C" fn(),
-    pub scan_finalizer_tbl_roots: extern "C" fn(),
     pub scan_end_proc_roots: extern "C" fn(),
     pub scan_global_tbl_roots: extern "C" fn(),
+    pub scan_yjit_roots: extern "C" fn(),
+    pub scan_finalizer_tbl_roots: extern "C" fn(),
     pub scan_obj_to_id_tbl_roots: extern "C" fn(),
     pub scan_misc_roots: extern "C" fn(),
     pub scan_final_jobs_roots: extern "C" fn(),

mmtk/src/scanning.rs

@@ -79,9 +79,10 @@ impl Scanning<Ruby> for VMScanning {
         let gc_tls = unsafe { GCThreadTLS::from_vwt_check(tls) };
         let root_scanning_work_packets: Vec<Box<dyn GCWork<Ruby>>> = vec![
             Box::new(ScanVMRoots::new(factory.clone())),
-            Box::new(ScanFinalizerTblRoots::new(factory.clone())),
             Box::new(ScanEndProcRoots::new(factory.clone())),
             Box::new(ScanGlobalTblRoots::new(factory.clone())),
+            Box::new(ScanYjitRoots::new(factory.clone())),
+            Box::new(ScanFinalizerTblRoots::new(factory.clone())),
             Box::new(ScanObjToIdTblRoots::new(factory.clone())),
             Box::new(ScanMiscRoots::new(factory.clone())),
             Box::new(ScanFinalJobsRoots::new(factory.clone())),
@@ -241,10 +242,6 @@ define_global_root_scanner!(ScanVMRoots, {
     (crate::upcalls().scan_vm_roots)();
 });
 
-define_global_root_scanner!(ScanFinalizerTblRoots, {
-    (crate::upcalls().scan_finalizer_tbl_roots)();
-});
-
 define_global_root_scanner!(ScanEndProcRoots, {
     (crate::upcalls().scan_end_proc_roots)();
 });
@@ -253,6 +250,14 @@ define_global_root_scanner!(ScanGlobalTblRoots, {
     (crate::upcalls().scan_global_tbl_roots)();
 });
 
+define_global_root_scanner!(ScanYjitRoots, {
+    (crate::upcalls().scan_yjit_roots)();
+});
+
+define_global_root_scanner!(ScanFinalizerTblRoots, {
+    (crate::upcalls().scan_finalizer_tbl_roots)();
+});
+
 define_global_root_scanner!(ScanObjToIdTblRoots, {
     (crate::upcalls().scan_obj_to_id_tbl_roots)();
 });