Remove unused ChainStruct

Source/missiles.cpp

@@ -34,9 +34,6 @@ bool MissilePreFlag;
 
 namespace {
 
-ChainStruct chain[MAXMISSILES];
-int numchains;
-
 int AddClassHealingBonus(int hp, HeroClass heroClass)
 {
 	switch (heroClass) {
@@ -1226,12 +1223,6 @@ void InitMissiles()
 		AvailableMissiles[i] = i;
 		ActiveMissiles[i] = 0;
 	}
-	numchains = 0;
-	for (auto &link : chain) {
-		link.idx = -1;
-		link._mitype = MIS_ARROW;
-		link._mirange = 0;
-	}
 	for (int j = 0; j < MAXDUNY; j++) {
 		for (int i = 0; i < MAXDUNX; i++) { // NOLINT(modernize-loop-convert)
 			dFlags[i][j] &= ~DungeonFlag::Missile;

Source/missiles.h

@@ -20,12 +20,6 @@ namespace devilution {
 
 constexpr Point GolemHoldingCell = Point { 1, 0 };
 
-struct ChainStruct {
-	int idx;
-	missile_id _mitype;
-	int _mirange;
-};
-
 struct MissilePosition {
 	Point tile;
 	/** Sprite's pixel offset from tile. */