Make SECTION size overflow non-fatal

Fixes #538

test/asm/load-overflow.asm

@@ -1,5 +1,25 @@
 SECTION "Overflow", ROM0
 	ds $6000
 LOAD "oops",WRAM0
+	; We might get an error for "oops", but it can also make sense to no-op the directive
 	ds $2001
+	; We shouldn't get any more errors for "Overflow" nor "oops"
+	db
 ENDL
+
+SECTION "Moar overflow", ROM0
+	ds $6001
+LOAD "hmm", WRAM0
+	ds $2000
+	; Since the `ds` overflows "Moar overflow", it could be no-op'd, making this `db` not error
+	db
+ENDL
+
+SECTION "Not overflowing", ROM0
+	ds $5FFF
+LOAD "lol", WRAM0
+	ds $2000
+	db
+	; Since the LOAD block is overflowed, this may be no-op'd, not affecting the "parent"
+ENDL
+	dw ; This, however...