Implement builtin bitwise intrinsics in SMT2 incremental decision pro…

[tautschnig]

…cedure

• Add support for __builtin_clzl (count leading zeros)
• Add support for __builtin_ctz (count trailing zeros)
• Add support for __builtin_ffs (find first set)
• Add support for __builtin_popcount (population count)
• Add support for __builtin_rotateleft* and rotate right (ID_rol, ID_ror)
• Add support for bitreverse_exprt (bit reverse)
• Add support for ID_bitnand (bitwise nand)

Implements conversion to SMT terms for each intrinsic with proper bit-vector operations.

Fixes: #8055

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