This is a tool to combine the FIDL JSON IR from multiple different library IRs into a single one. This is most useful for capturing a whole Fuchsia platform's IR in a single file.
The JSON that this tool produces differs from the IR produced by fidlc, consumed by fidlgens and defined in tools/fidlc/schema.json. It omits the name and maybe_attributes at the top-level since these are per-library. It omits library_dependencies since this IR must not have any external dependencies and declaration_order because it‘s more trouble than it’s worth.
It‘s an error for the tool to receive more than one input with the same library defined (ie: duplicate top-level name). It’s an error for inputs to have different experiments enabled. All referenced declarations must be provided.