Update to MMTK core PR #1159 (#283)

Co-authored-by: mmtkgc-bot <mmtkgc.bot@gmail.com>

Author: qinsoon

mmtk/Cargo.lock

@@ -34,7 +34,7 @@ cfg-if = "1.0"
 # - change branch
 # - change repo name
 # But other changes including adding/removing whitespaces in commented lines may break the CI.
-mmtk = { git = "https://github.com/mmtk/mmtk-core.git", rev = "6cae51c40104d84bb74598ab3eba4f9ef8173e8e" }
+mmtk = { git = "https://github.com/mmtk/mmtk-core.git", rev = "a3a72f8e5795678eff06fdc1524f0b429a62ccc0" }
 # Uncomment the following to build locally
 # mmtk = { path = "../repos/mmtk-core" }
 

mmtk/Cargo.toml

@@ -87,18 +87,11 @@ impl<const COMPRESSED: bool> ObjectModel<OpenJDK<COMPRESSED>> for VMObjectModel<
         object.to_raw_address()
     }
 
-    fn ref_to_address(object: ObjectReference) -> Address {
-        object.to_raw_address()
-    }
-
     fn ref_to_header(object: ObjectReference) -> Address {
         object.to_raw_address()
     }
 
-    fn address_to_ref(address: Address) -> ObjectReference {
-        debug_assert!(!address.is_zero());
-        unsafe { ObjectReference::from_raw_address_unchecked(address) }
-    }
+    const IN_OBJECT_ADDRESS_OFFSET: isize = 0;
 
     fn dump_object(object: ObjectReference) {
         unsafe {