Add an explicit unrestricted_float converter to the shared WebIDL value and derive infrastructure. Preserve signed zero, NaN and infinities while rounding finite numbers to binary32; required arity, conversion side effects and original exceptions retain the existing contracts. Cross-realm tests compare Math.fround and check callee-realm TypeError.
Add the WebIDL restricted float converter and f32 inference in generated argument and dictionary bindings. Round finite numbers to binary32, reject values that become nonfinite, and preserve exceptions from numeric conversion.
Regression coverage compares rounding with V8 Math.fround, including signed zero, subnormals and overflow, and checks implicit/explicit derived argument conversion, single coercion, exception identity and the callee TypeError realm. Extracted from the AudioBuffer commit without an audio runtime dependency.
ldm0