Add mono_unity_gc_is_disabled

Use Boehm GC_ functions in mono_unity_gc_enable/disable instead of mono_gc_ functions.

unity/unity_utils.c

@@ -13,7 +13,10 @@
 #include <mono/metadata/threads.h>
 #include <mono/metadata/tokentype.h>
 #include <mono/utils/mono-string.h>
-#include <mono/metadata/gc-internal.h>
+
+#if HAVE_BOEHM_GC	
+#include <libgc/include/gc.h>
+#endif
 
 #include <glib.h>
 
@@ -327,10 +330,28 @@ mono_unity_install_unitytls_interface(mono_unity_unitytls_interface* callbacks)
 
 void mono_unity_gc_enable()
 {
-	mono_gc_enable();
+#if HAVE_BOEHM_GC	
+	GC_enable ();
+#else
+	g_assert_not_reached ();
+#endif
 }
 
 void mono_unity_gc_disable()
 {
-	mono_gc_disable();
+#if HAVE_BOEHM_GC	
+	GC_disable ();
+#else
+	g_assert_not_reached ();
+#endif
+}
+
+int mono_unity_gc_is_disabled()
+{
+#if HAVE_BOEHM_GC
+	return GC_dont_gc != 0;
+#else
+	g_assert_not_reached ();
+	return 0;
+#endif
 }

unity/unity_utils.h

@@ -50,5 +50,6 @@ void mono_unity_install_unitytls_interface(mono_unity_unitytls_interface* callba
 // gc
 void mono_unity_gc_enable();
 void mono_unity_gc_disable();
+int mono_unity_gc_is_disabled();
 
 #endif