[Feature #20470] Split GC into gc_impl.c

This commit splits gc.c into two files:

- gc.c now only contains code not specific to Ruby GC. This includes
  code to mark objects (which the GC implementation may choose not to
  use) and wrappers for internal APIs that the implementation may need
  to use (e.g. locking the VM).

- gc_impl.c now contains the implementation of Ruby's GC. This includes
  marking, sweeping, compaction, and statistics. Most importantly,
  gc_impl.c only uses public APIs in Ruby and a limited set of functions
  exposed in gc.c. This allows us to build gc_impl.c independently of
  Ruby and plug Ruby's GC into itself.

1 files changed, 2 insertions, 2 deletions

diff --git a/imemo.c b/imemo.c
index 088185b195..bf852e8809 100644
--- a/imemo.c
+++ b/imemo.c
@@ -214,7 +214,7 @@ rb_cc_table_mark(VALUE klass)
 static bool
 moved_or_living_object_strictly_p(VALUE obj)
 {
-    return obj && (rb_objspace_markable_object_p(obj) || BUILTIN_TYPE(obj) == T_MOVED);
+    return obj && (!rb_objspace_garbage_object_p(obj) || BUILTIN_TYPE(obj) == T_MOVED);
 }
 
 static void
@@ -457,7 +457,7 @@ vm_ccs_free(struct rb_class_cc_entries *ccs, int alive, VALUE klass)
             if (!alive) {
                 void *ptr = asan_unpoison_object_temporary((VALUE)cc);
                 // ccs can be free'ed.
-                if (rb_objspace_markable_object_p((VALUE)cc) &&
+                if (!rb_objspace_garbage_object_p((VALUE)cc) &&
                     IMEMO_TYPE_P(cc, imemo_callcache) &&
                     cc->klass == klass) {
                     // OK. maybe target cc.