fxconv: copy elements in += ObjectData instead of referencing subobject

This way, after o1 += o2, when o1 is linked all the outer data of o2 is
linked alongside the outer data of o1, and the inner data remains
contiguous. This is important for arrays, where we don't want the outer
data of o2 to appear before the next inner field of o1.

With this commit, an update to o2 after o1 += o2 no longer updates o1.
This wasn't a feature in the first place.

fxconv/fxconv.py

@@ -250,7 +250,7 @@ class ObjectData:
 		elif isinstance(other, Sym):
 			self.inner.append(other)
 		elif isinstance(other, ObjectData):
-			self.inner.append(other)
+			self.inner += other.inner
 		return self
 
 	@staticmethod
@@ -273,22 +273,10 @@ class ObjectData:
 		return padding
 
 	def link(self, symbol):
-		inner = []
+		inner = self.inner
 		outer = []
 		elements = []
-		size = 0
-
-		# First unfold all structures within [inner] as we accumulate the total
-		# size of the inner data
-		for el in self.inner:
-			if isinstance(el, ObjectData):
-				size += self.align(size, el.alignment, inner)
-				code, code_size = el.link(f"{symbol} + {size}")
-				inner.append((code, code_size))
-				size += code_size
-			else:
-				inner.append(el)
-				size += self.element_size(el)
+		size = sum(self.element_size(el) for el in inner)
 
 		# Then replace complex references with unfolded data appended at the
 		# end of the structure