evalengine: Proper support for bit literals

[vmg]

Description

We weren't handling bit literals properly, neither in the sqlparser, nor the evalengine.

The first problem we had was in the parser: the bind var extractor was normalizing all Bit literals as hex, which is not correct. There's an actual difference between hex and bits in MySQL: in a numerical context, hex is handled as an unsigned integer but bits are handled as a signed integer. So the parser must maintain the difference between them.

I normalized the parser to generate BitNum literals for all bit literals. Unlike for hex, where HexVal (x'aabbccdd') and HexNum (0xaabbccdd) are handled differently during evaluation, both kinds of bit literals 0b0101 and b'0101' are handled identically, so we don't need to expose both literal types. We now normalize everything to the earlier "numeric" form with the 0b prefix because it's easier to handle.

With these changes to the parser in place, we can update the evalengine to take into account the new types during evaluation.

cc @dbussink @systay

Related Issue(s)

• evalengine: serialize to SQL #14337

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[systay]

lgtm