Retire RUBY_MARK_UNLESS_NULL

Marking `Qnil` or `Qfalse` works fine, having
an extra macro to avoid it isn't needed.

internal/gc.h

@@ -79,14 +79,6 @@ rb_gc_debug_body(const char *mode, const char *msg, int st, void *ptr)
 #define RUBY_GC_INFO if(0)printf
 #endif
 
-#define RUBY_MARK_MOVABLE_UNLESS_NULL(ptr) do { \
-    VALUE markobj = (ptr); \
-    if (RTEST(markobj)) {rb_gc_mark_movable(markobj);} \
-} while (0)
-#define RUBY_MARK_UNLESS_NULL(ptr) do { \
-    VALUE markobj = (ptr); \
-    if (RTEST(markobj)) {rb_gc_mark(markobj);} \
-} while (0)
 #define RUBY_FREE_UNLESS_NULL(ptr) if(ptr){ruby_xfree(ptr);(ptr)=NULL;}
 
 #if STACK_GROW_DIRECTION > 0

vm.c

@@ -2963,7 +2963,7 @@ rb_vm_mark(void *ptr)
         rb_gc_mark_movable(vm->mark_object_ary);
         rb_gc_mark_movable(vm->load_path);
         rb_gc_mark_movable(vm->load_path_snapshot);
-        RUBY_MARK_MOVABLE_UNLESS_NULL(vm->load_path_check_cache);
+        rb_gc_mark_movable(vm->load_path_check_cache);
         rb_gc_mark_movable(vm->expanded_load_path);
         rb_gc_mark_movable(vm->loaded_features);
         rb_gc_mark_movable(vm->loaded_features_snapshot);
@@ -2971,8 +2971,8 @@ rb_vm_mark(void *ptr)
         rb_gc_mark_movable(vm->loaded_features_realpath_map);
         rb_gc_mark_movable(vm->top_self);
         rb_gc_mark_movable(vm->orig_progname);
-        RUBY_MARK_MOVABLE_UNLESS_NULL(vm->coverages);
-        RUBY_MARK_MOVABLE_UNLESS_NULL(vm->me2counter);
+        rb_gc_mark_movable(vm->coverages);
+        rb_gc_mark_movable(vm->me2counter);
 
         if (vm->loading_table) {
             rb_mark_tbl(vm->loading_table);
@@ -3394,16 +3394,16 @@ rb_execution_context_mark(const rb_execution_context_t *ec)
                              sizeof(ec->machine.regs) / (sizeof(VALUE)));
     }
 
-    RUBY_MARK_UNLESS_NULL(ec->errinfo);
-    RUBY_MARK_UNLESS_NULL(ec->root_svar);
+    rb_gc_mark(ec->errinfo);
+    rb_gc_mark(ec->root_svar);
     if (ec->local_storage) {
         rb_id_table_foreach_values(ec->local_storage, mark_local_storage_i, NULL);
     }
-    RUBY_MARK_UNLESS_NULL(ec->local_storage_recursive_hash);
-    RUBY_MARK_UNLESS_NULL(ec->local_storage_recursive_hash_for_trace);
-    RUBY_MARK_UNLESS_NULL(ec->private_const_reference);
+    rb_gc_mark(ec->local_storage_recursive_hash);
+    rb_gc_mark(ec->local_storage_recursive_hash_for_trace);
+    rb_gc_mark(ec->private_const_reference);
 
-    RUBY_MARK_MOVABLE_UNLESS_NULL(ec->storage);
+    rb_gc_mark_movable(ec->storage);
 }
 
 void rb_fiber_mark_self(rb_fiber_t *fib);
@@ -3434,8 +3434,8 @@ thread_mark(void *ptr)
     switch (th->invoke_type) {
       case thread_invoke_type_proc:
       case thread_invoke_type_ractor_proc:
-        RUBY_MARK_UNLESS_NULL(th->invoke_arg.proc.proc);
-        RUBY_MARK_UNLESS_NULL(th->invoke_arg.proc.args);
+        rb_gc_mark(th->invoke_arg.proc.proc);
+        rb_gc_mark(th->invoke_arg.proc.args);
         break;
       case thread_invoke_type_func:
         rb_gc_mark_maybe((VALUE)th->invoke_arg.func.arg);
@@ -3445,21 +3445,21 @@ thread_mark(void *ptr)
     }
 
     rb_gc_mark(rb_ractor_self(th->ractor));
-    RUBY_MARK_UNLESS_NULL(th->thgroup);
-    RUBY_MARK_UNLESS_NULL(th->value);
-    RUBY_MARK_UNLESS_NULL(th->pending_interrupt_queue);
-    RUBY_MARK_UNLESS_NULL(th->pending_interrupt_mask_stack);
-    RUBY_MARK_UNLESS_NULL(th->top_self);
-    RUBY_MARK_UNLESS_NULL(th->top_wrapper);
+    rb_gc_mark(th->thgroup);
+    rb_gc_mark(th->value);
+    rb_gc_mark(th->pending_interrupt_queue);
+    rb_gc_mark(th->pending_interrupt_mask_stack);
+    rb_gc_mark(th->top_self);
+    rb_gc_mark(th->top_wrapper);
     if (th->root_fiber) rb_fiber_mark_self(th->root_fiber);
 
     RUBY_ASSERT(th->ec == rb_fiberptr_get_ec(th->ec->fiber_ptr));
-    RUBY_MARK_UNLESS_NULL(th->stat_insn_usage);
-    RUBY_MARK_UNLESS_NULL(th->last_status);
-    RUBY_MARK_UNLESS_NULL(th->locking_mutex);
-    RUBY_MARK_UNLESS_NULL(th->name);
+    rb_gc_mark(th->stat_insn_usage);
+    rb_gc_mark(th->last_status);
+    rb_gc_mark(th->locking_mutex);
+    rb_gc_mark(th->name);
 
-    RUBY_MARK_UNLESS_NULL(th->scheduler);
+    rb_gc_mark(th->scheduler);
 
     RUBY_MARK_LEAVE("thread");
 }