What was wrong?

Currently, the compiler would only outputs the bytecode that is used for contract deployment but not the runtime bytecode that is later saved to storage and can be read out from the blockchain.

Being able to obtain the runtime bytecode is useful for contract verification.

How was it fixed?

Basically just expose the deployedBytecode that solc already gives us.
Note:

• I named the file mycontract.runtime.bin because I find the term runtime bytecode less ambigious than deployed bytecode
• Producing runtime bytecode is another variant of the --emit options. Note that the default did NOT change from abi, bytecode because there are certain contracts where we currently can not produce runtime bytecode for. These seem to be contracts that use create/create2 in __init__.
• Related to the former point, getting the runtime bytecode is on demand e.g. --emit abi,bytecode,runtime-bytecode