Remove unused patch (after 3.6.0 update)

lang/mono/patches/patch-dg

@@ -1,56 +0,0 @@
-$NetBSD: patch-dg,v 1.7 2013/11/15 14:01:45 joerg Exp $
-
---- mono/metadata/threads.c.orig	2013-04-25 09:07:19.000000000 +0000
-+++ mono/metadata/threads.c
-@@ -86,6 +86,8 @@ size_t pthread_get_stacksize_np(pthread_
- #   endif
- #endif
- 
-+static int tls_key_initialised;
-+
- struct StartInfo 
- {
- 	guint32 (*func)(void *);
-@@ -634,7 +636,8 @@ static guint32 WINAPI start_wrapper_inte
- 	 * Boehm GC - the io-layer keeps a GC-visible hash of pointers
- 	 * to TLS data.)
- 	 */
--	SET_CURRENT_OBJECT (NULL);
-+	if (tls_key_initialised)
-+		SET_CURRENT_OBJECT (NULL);
- 
- 	return(0);
- }
-@@ -881,8 +884,16 @@ mono_thread_get_stack_bounds (guint8 **s
- #    if !defined(__OpenBSD__)
- 	pthread_attr_getstack (&attr, (void**)staddr, stsize);
- #    endif
-+	/*
-+	 * he@NetBSD.org: For some reason, this test fails on NetBSD/powerpc,
-+	 * so just avoid it.
-+	 * kefren@: as a hint if somebody want to take a closer look: this
-+	 * triggers also when building in a i386 chroot on amd64
-+	 */
-+#   if !(defined(__NetBSD__) && defined(__powerpc__))
- 	if (*staddr)
- 		g_assert ((current > *staddr) && (current < *staddr + *stsize));
-+#   endif
- #  endif
- 
- 	pthread_attr_destroy (&attr);
-@@ -2573,6 +2584,7 @@ void mono_thread_init (MonoThreadStartCB
- 
- 	MONO_FAST_TLS_INIT (tls_current_object);
- 	mono_native_tls_alloc (&current_object_key, NULL);
-+	tls_key_initialised = 1;
- 	THREAD_DEBUG (g_message ("%s: Allocated current_object_key %d", __func__, current_object_key));
- 
- 	mono_thread_start_cb = start_cb;
-@@ -2616,6 +2628,7 @@ void mono_thread_cleanup (void)
- #endif
- 
- 	mono_native_tls_free (current_object_key);
-+	tls_key_initialised = 0;
- }
- 
- void