1. A method for synthesizing a behavioral description of a circuit into a structural description of the circuit, the method comprising: using a processor to receive the behavioral description of the circuit, the behavioral description of the circuit including: a behavioral description of a first circuit portion, the behavioral description of the first circuit portion including a representation of: a first component that is to provide a first type of functionality; and a behavioral description of a second circuit portion, the behavioral description of the second circuit portion including representations of: a second component that is to provide the first type of functionality; and at least one other component that is to provide another type of functionality that is not provided by any component described in the behavioral description of the first circuit portion; and using a processor to synthesize the structural description of the circuit from the behavioral description of the circuit such that the structural description of the circuit includes: a structural description of a shared circuit portion, the structural description of the shared circuit portion including a structural description of circuitry that is to provide the first type of functionality; a structural description of the first circuit portion, the structural description of the first circuit portion including a structural representation of: a first interface to the shared circuit portion instead of an individual structural description of the circuitry that is to provide the first type of functionality; and a structural description of the second circuit portion, the structural description of the second circuit portion including a structural representation of: a second interface to the shared circuit portion instead of a structural description of the circuitry that is to provide the first type of functionality; and the at least one other component.