Reads 8 bytes from array starting at offset as big-endian
signed 64-bit integer and returns it.
IMPORTANT: due to JavaScript limitation, supports exact
numbers in range -9007199254740991 to 9007199254740991.
If the number stored in the byte array is outside this range,
the result is not exact.
Reads 8 bytes from array starting at offset as big-endian signed 64-bit integer and returns it.
IMPORTANT: due to JavaScript limitation, supports exact numbers in range -9007199254740991 to 9007199254740991. If the number stored in the byte array is outside this range, the result is not exact.