Fix Item_8026AD20 argument

[g-guthrie]

What changed

• Add the retail fifth integer argument to Item_8026AD20's declaration and definition.
• Pass 1 from the forward-throw path and 0 from the backward-throw path in ftCo_80095EFC.

Why

The retail ftCo_80095EFC call sites materialize r6 immediately before both Item_8026AD20 calls. The current four-argument prototype omitted those instructions even though the callee does not consume the value.

Impact

This restores both missing call-site instructions and improves the remaining unmatched function without changing Item_8026AD20's body behavior.

Validation

• Exact MWCC GC/1.2.5n compile of ftCo_ItemThrow.c and item.c
• Function scorer: removed two missing instructions from ftCo_80095EFC (penalty 1410 to 1210)
• python3 tools/check/main.py --fix --quiet
• clang-format 22.1.0 --dry-run --Werror
• git diff --check

[decomp-dev]

Report for GALE01 (63e4e8a - 0c8bc7a)

📈 1 improvement in an unmatched item

Unit	Item	Bytes	Before	After
main/melee/ft/chara/ftCommon/ftCo_ItemThrow	ftCo_80095EFC	+19	90.02%	93.53%