Refactored SEA IR folder structure to be more logical.

Change-Id: I302c79af92c07cceb38dff36efe416bfa4869a91
diff --git a/compiler/sea_ir/debug/dot_gen.h b/compiler/sea_ir/debug/dot_gen.h
index 301c70f..675d83d 100644
--- a/compiler/sea_ir/debug/dot_gen.h
+++ b/compiler/sea_ir/debug/dot_gen.h
@@ -20,7 +20,7 @@
 #include "safe_map.h"
 #include "base/stringprintf.h"
 #include "file_output_stream.h"
-#include "sea_ir/sea.h"
+#include "sea_ir/ir/sea.h"
 #include "sea_ir/types/type_inference.h"
 
 namespace sea_ir {