Fix Variant int64 example binary data

[alamb]

• Closes primitive_int64.value maybe an int32 type #82

As @mapleFU pointed out, the binary vale of primtive_int64 actually contains an int32 as it appears Spark truncates variant values to the smallest type that will fit it

Changes

1. Update the regeneration script
2. Rerun the script
3. Check in the results

I also manually verified the output binary is correct:

$ xxd primitive_int64.value
00000000: 1815 81e9 7df4 1022 11                   ....}..".

we see the first byte is 0x18

the first byte 0x18 is 0b00011000

• low 2 bits are 0b00 => Primitive type
• high 6 bits are 0b000110 ==> 6

Per the encoding grammar for Variant basic types) table, primitive_type = 6 corresponds to int64:

Exact Numeric	int8	3	INT(8, signed)	1 byte
Exact Numeric	int16	4	INT(16, signed)	2 byte little-endian
Exact Numeric	int32	5	INT(32, signed)	4 byte little-endian
Exact Numeric	int64	6	INT(64, signed)	8 byte little-endian

[Fokko]

Good catch @mapleFU, and thanks for the fix @alamb 🙌