Fix some pokecrystal bug and glitches (#8)

Credits sequence changes move selection menu behavior; Swimming NPCs aren't limited by their movement radius; No bump noise if standing on tile E; The unused phonecall script command may crash; ScriptCall can overflow wScriptStack and crash; LoadSpriteGFX does not limit the capacity of UsedSprites; ReadObjectEvents overflows into wObjectMasks; ClearWRAM only clears WRAM bank 1; BattleAnimCmd_ClearObjs only clears the first 6⅔ objects; Options menu fails to clear joypad state on initialization

engine/overworld/events.asm

@@ -543,13 +543,12 @@ TryObjectEvent:
 	ld a, [hl]
 	and MAPOBJECT_TYPE_MASK
 
-; BUG: TryObjectEvent arbitrary code execution (see docs/bugs_and_glitches.md)
 	push bc
 	ld de, 3
 	ld hl, ObjectEventTypeArray
 	call IsInArray
-	jr nc, .nope
 	pop bc
+	jr nc, .nope
 
 	inc hl
 	ld a, [hli]

engine/overworld/npc_movement.asm

@@ -4,10 +4,10 @@ CanObjectMoveInDirection:
 	bit SWIMMING_F, [hl]
 	jr z, .not_swimming
 
-; BUG: Swimming NPCs aren't limited by their movement radius (see docs/bugs_and_glitches.md)
 	ld hl, OBJECT_FLAGS1
 	add hl, bc
 	bit NOCLIP_TILES_F, [hl]
+	jr nz, .noclip_tiles
 	push hl
 	push bc
 	call WillObjectBumpIntoLand

engine/overworld/overworld.asm

@@ -316,8 +316,6 @@ AddSpriteGFX:
 	ret
 
 LoadSpriteGFX:
-; BUG: LoadSpriteGFX does not limit the capacity of UsedSprites (see docs/bugs_and_glitches.md)
-
 	ld hl, wUsedSprites
 	ld b, SPRITE_GFX_LIST_CAPACITY
 .loop
@@ -335,7 +333,9 @@ LoadSpriteGFX:
 	ret
 
 .LoadSprite:
+	push de
 	call GetSprite
+	pop de
 	ld a, l
 	ret
 

engine/overworld/player_movement.asm

@@ -391,9 +391,9 @@ DoPlayerMovement::
 	db FACE_UP | FACE_LEFT    ; COLL_HOP_UP_LEFT
 
 .CheckWarp:
-; BUG: No bump noise if standing on tile $3E (see docs/bugs_and_glitches.md)
-
 	ld a, [wWalkingDirection]
+	cp STANDING
+	jr z, .not_warp
 	ld e, a
 	ld d, 0
 	ld hl, .EdgeWarps
@@ -405,8 +405,6 @@ DoPlayerMovement::
 	ld a, TRUE
 	ld [wWalkingIntoEdgeWarp], a
 	ld a, [wWalkingDirection]
-	cp STANDING
-	jr z, .not_warp
 
 	ld e, a
 	ld a, [wPlayerDirection]

engine/overworld/scripting.asm

@@ -1238,12 +1238,13 @@ Script_memcall:
 	; fallthrough
 
 ScriptCall:
-; BUG: ScriptCall can overflow wScriptStack and crash (see docs/bugs_and_glitches.md)
-
-	push de
 	ld hl, wScriptStackSize
-	ld e, [hl]
+	ld a, [hl]
+	cp 5
+	ret nc
+	push de
 	inc [hl]
+	ld e, a
 	ld d, 0
 	ld hl, wScriptStack
 	add hl, de