Update to MMTk core PR #1308 (#238)

Co-authored-by: mmtkgc-bot <[email protected]>

Author: qinsoon

mmtk/Cargo.lock

@@ -27,7 +27,7 @@ lazy_static = "1.1"
 # - 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 = "42a434bf2280b0a9e10439cc7061a0f07af83d71" }
+mmtk = { git = "https://github.com/mmtk/mmtk-core.git", rev = "c5ead72a87bcc8cc49b5e7a62cf71d848b4b4c9b" }
 # Uncomment the following to build locally
 # mmtk = { path = "../repos/mmtk-core" }
 log = {version = "0.4", features = ["max_level_trace", "release_max_level_off"] }

mmtk/Cargo.toml

@@ -21,7 +21,7 @@ typedef struct {
 #define MAX_BUMP_ALLOCATORS 6
 #define MAX_LARGE_OBJECT_ALLOCATORS 2
 #define MAX_MALLOC_ALLOCATORS 1
-#define MAX_IMMIX_ALLOCATORS 1
+#define MAX_IMMIX_ALLOCATORS 2
 #define MAX_FREE_LIST_ALLOCATORS 2
 #define MAX_MARK_COMPACT_ALLOCATORS 1