GH-106008: Make implicit boolean conversions explicit

[brandtbucher]

...and specialize them!

This adds a new TO_BOOL bytecode that prefixes all UNARY_NOT, POP_JUMP_IF_TRUE, and POP_JUMP_IF_FALSE instructions, which now require an exact boolean. We also use a spare bit in COMPARE_OP's oparg to indicate whether the result should be converted to bool (this saves a TO_BOOL for most branches, and is a no-op for all COMPARE_OP specializations).

"0% faster". Stats show a 93.5% hit rate for the new instructions.

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📚 Documentation preview 📚: https://cpython-previews--106003.org.readthedocs.build/

• Issue: Make implicit boolean conversions explicit #106008