Line numbers in error messages

[nano-o]

A line number would be convenient in the error message below.
In general a standard error-message format would be great (with line numbers when applicable) in order to set up my editor to jump to errors automatically (in this case vim).

PASS #1: TypeCheckerSnowcat                                       I@21:37:44.350
 > Running Snowcat .::.                                           I@21:37:44.350
Parsing error in the type annotation:  P -> [P -> Bool]           E@21:37:44.430
<unknown>: type input error: Parser error in type annotation of m2: ':' expected but -> found E@21:37:44.450
It took me 0 days  0 hours  0 min  0 sec                          I@21:37:44.451
Total time: 0.564 sec                                             I@21:37:44.451
EXITCODE: ERROR (255)

[shonfeder]

Thank you for the report!

This relates to #955 and #943.