Add printErrorLn to common.mc

[br4sco]

No description provided.

[marten-voorberg]

Minor note on the naming here. Since we have print and printLn for outputing to stdout, should we maybe call this errorLn for consistency?

[br4sco]

Minor note on the naming here. Since we have print and printLn for outputing to stdout, should we maybe call this errorLn for consistency?

We have an intrinsic error, which exists in a program with an error code (and a message). I named it printErrorLn because we have an intrinsic, printError, which prints a string to stderr without a newline without exiting the program (hence the same naming convention as print and printLn)