This enhancement systematizes handling of SharedRuntime stubs. A unique (enum) id is generated for each stub. Declarations/definitions for each stub's name and the static field storing its associated blob are generated based on declarations of the relevant properties in a simple, independent macro format.

Static field names remain the same so no consequent changes are required to client code that references these fields. Shared stub generator code is modified to employ the generated stub ids and names uniformly.

This is the first of several related enhancements. Similar changes will systematize handling of C1_Runtime and Opto_Runtime stubs and stubs generated by StubGenerator.