Ryu's tables (Ulf Adams, "Ryu: fast float-to-string conversion",
PLDI 2018; ulfjack/ryu d2s_full_table.h), generated: entry i is two
u64, low then high, of 5^i to 125 bits (POW5) and of 2^(bits(5^i) - 1
+ 125) / 5^i + 1 (POW5_INV).

ryu.bin holds them as little-endian u64: POW5_INV's 342 entries (684 u64)
from byte 0, then POW5's 326 entries (652 u64) from byte 5472. Computed,
not copied: there is no input file.

To regenerate, from the repository root:

    tape build stdlib/conv/regen.tape -o regen.exe
    regen.exe stdlib/conv

The output depends only on the formulas: a run gives an empty diff.
