Consolidate float-to-C++ literal generation into Utils::genFloatLiteral().
Previously:
- genCValue() stringified floats directly via (string), emitting 'INF', '-INF', 'NAN', or losing the floating-point decimal point for whole numbers like 1.0 -> '1'.
- BinaryOpTrait::genFloatLiteral() used sprintf('%.17g') without handling INF or NAN.
Now all float code generation paths delegate to Utils::genFloatLiteral(), mapping INF/-INF/NAN to std::numeric_limits<double> and ensuring whole numbers retain .0.