Forward declare struct Section to avoid a nested header include

include/link/output.hpp

@@ -3,7 +3,7 @@
 #ifndef RGBDS_LINK_OUTPUT_HPP
 #define RGBDS_LINK_OUTPUT_HPP
 
-#include "link/section.hpp"
+struct Section;
 
 /*
  * Registers a section for output.

src/asm/opt.cpp

@@ -10,7 +10,6 @@
 #include "asm/fixpoint.hpp"
 #include "asm/fstack.hpp"
 #include "asm/lexer.hpp"
-#include "asm/main.hpp"
 #include "asm/section.hpp"
 #include "asm/warning.hpp"
 

src/link/output.cpp

@@ -17,6 +17,7 @@
 #include "platform.hpp"
 
 #include "link/main.hpp"
+#include "link/section.hpp"
 #include "link/symbol.hpp"
 
 #define BANK_SIZE 0x4000