Quickly reject tar entries > 2^60 bytes w/o risking overflow (#2263)

Quickly reject tar entries > 2^60 bytes w/o risking overflow (#2263)

In particular, this ensures that we cannot overflow rounding-up
calculations. Recent tar changes put in a lot of sanity limits on the
sizes of particular kinds of data, but the usual behavior in most cases
was to skip over-large values. The skipping behavior required
rounding-up and accumulating values that could potentially overflow
64-bit integers. This adds some coarser checks that fail more directly
when an entry claims to be more than 1 exbibyte (2^60 bytes), avoiding
any possibility of numeric overflow along these paths.

OSS-Fuzz Issue: 70062