3e0a992a3f doc: Clarify comments about endianness after #30526 (Ryan Ofsky)
Pull request description:
This is a documentation-only change following up on suggestions made in the #30526 review.
Motivation for this change is that I was recently reviewing #31583, which reminded me how confusing the arithmetic blob code was and made me want to write better comments.
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achow101:
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TheCharlatan:
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Sjors:
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BrandonOdiwuor:
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Tree-SHA512: 90d5582a25a51fc406d83ca6b8c4e5e4d3aee828a0497f4b226b2024ff89e29b9b50d0ae8ddeac6abf2757fe78548d58cf3dd54df4b6d623f634a2106048091d