Fix 39e90ec: Integers for scripts are 64bit, but saved as 32bit (#9415)

(cherry picked from commit ddafc0de05)

src/saveload/extended_ver_sl.cpp

@@ -157,6 +157,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_DEPOT_ORDER_EXTRA_FLAGS,XSCF_IGNORABLE_UNKNOWN,   1,   1, "depot_order_extra_flags",   nullptr, nullptr, nullptr        },
 	{ XSLFI_EXTRA_SIGNAL_TYPES,     XSCF_NULL,                1,   1, "extra_signal_types",        nullptr, nullptr, nullptr        },
 	{ XSLFI_BANKRUPTCY_EXTRA,       XSCF_NULL,                1,   1, "bankruptcy_extra",          nullptr, nullptr, nullptr        },
+	{ XSLFI_SCRIPT_INT64,           XSCF_NULL,                1,   1, "script_int64",              nullptr, nullptr, nullptr        },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, nullptr, nullptr, nullptr, nullptr },// This is the end marker
 };
 

src/saveload/extended_ver_sl.h

@@ -111,6 +111,7 @@ enum SlXvFeatureIndex {
 	XSLFI_DEPOT_ORDER_EXTRA_FLAGS,                ///< Depot order extra flags
 	XSLFI_EXTRA_SIGNAL_TYPES,                     ///< Extra signal types
 	XSLFI_BANKRUPTCY_EXTRA,                       ///< Extra company bankruptcy fields
+	XSLFI_SCRIPT_INT64,                           ///< See: SLV_SCRIPT_INT64
 
 	XSLFI_RIFF_HEADER_60_BIT,                     ///< Size field in RIFF chunk header is 60 bit
 	XSLFI_HEIGHT_8_BIT,                           ///< Map tile height is 8 bit instead of 4 bit, but savegame version may be before this became true in trunk