Implement compact file stacks in object files

Gets rid of `open_memstream`, enabling Windows compatibility again
Also fixes #491 as a nice bonus!

include/link/object.h

@@ -14,8 +14,9 @@
 /**
  * Read an object (.o) file, and add its info to the data structures.
  * @param fileName A path to the object file to be read
+ * @param i The ID of the file
  */
-void obj_ReadFile(char const *fileName);
+void obj_ReadFile(char const *fileName, unsigned int i);
 
 /**
  * Perform validation on the object files' contents
@@ -27,6 +28,12 @@ void obj_DoSanityChecks(void);
  */
 void obj_CheckAssertions(void);
 
+/**
+ * Sets up object file reading
+ * @param nbFiles The number of object files that will be read
+ */
+void obj_Setup(unsigned int nbFiles);
+
 /**
  * `free`s all object memory that was allocated.
  */