cleanup: Include "irgraph_t.h" instead of "irgraph.h" internally.

ir/ana/cdep.c

@@ -11,7 +11,7 @@
 #include <assert.h>
 #include <stdlib.h>
 #include "irdom_t.h"
-#include "irgraph.h"
+#include "irgraph_t.h"
 #include "irgwalk.h"
 #include "irnode.h"
 #include "pmap.h"

ir/opt/parallelize_mem.c

@@ -15,7 +15,7 @@
 #include "array_t.h"
 #include "debug.h"
 #include "ircons.h"
-#include "irgraph.h"
+#include "irgraph_t.h"
 #include "irgmod.h"
 #include "irgopt.h"
 #include "irgwalk.h"