The Huffman repeat mode checker assumed that the CTable was zeroed in the region `[maxSymbolValue + 1, 256)`.
This assumption didn't hold for tables built in the dictionaries, because it didn't go through the same codepath.
Since this code was originally written, we added a header to the CTable that specifies the `tableLog`.
Add `maxSymbolValue` to that header, and check that the table's `maxSymbolValue` is at least the block's `maxSymbolValue`.
This solution is cleaner because we write this header for every CTable we build, so it can't be missed in any code path.
Credit to OSS-Fuzz
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