tests/indent: fix outdated or wrong comments

indent: remove support for form feed characters inside a line

Form feeds are occasionally used to split code into pages, and this use
is still supported. Having a form feed in the middle of a line is
exotic.

indent: remove broken code for handling blank lines

This fixes several bugs where blank lines were erroneously added or
removed, treating these old bugs for new bugs in different places.
These new bugs are expected to be easier to fix, as the old bugs will
not interfere anymore.

indent: remove buggy code for swapping tokens

It is not the job of an indenter to swap tokens, even if it's only about
placing comments elsewhere. The code that swapped the tokens was
complicated, buggy and impossible to understand.

In -br (brace right) mode, indent no longer moves a '{' from the
beginning of a line to the end of the previous line, as that was handled
by the token swapping code as well. This change is unintended, but it
will be easier to re-add that now that the code is simpler.

tests/indent: migrate token tests to other tests

In indent.h 1.49 from 2021-10-25, the enumeration token_type was split
into lexer_symbol and parser_symbol to more clearly express that these
tokens fall into completely different classes of usage patterns.

tests/indent: change directive from '#' to '//'

Using a '//' instead of '#' turns the directives into well-formed C
code, resulting in fewer error markers in the editor.

indent: remove FreeBSD IDs

Most of the IDs were empty anyway.

tests/indent: add skeletons for testing tokens and parser symbols

The constants that were previously defined in indent_codes.h were a wild
mixture of tokens from the lexer and symbols on the parser stack. They
were split into separate types starting at indent.h 1.49 from 2021-10-25
and finishing at 1.73 from 2021-10-31.

To match the tests with the new token names, the old tests need to be
migrated to the newly added tests. This will take some time so first
add the skeletons and migrate them in smaller steps, cleaning them up
and extending them on the way.

tests/indent: migrate token tests to other tests

In indent.h 1.49 from 2021-10-25, the enumeration token_type was split
into lexer_symbol and parser_symbol to more clearly express that these
tokens fall into completely different classes of usage patterns.

tests/indent: change directive from '#' to '//'

Using a '//' instead of '#' turns the directives into well-formed C
code, resulting in fewer error markers in the editor.

indent: remove FreeBSD IDs

Most of the IDs were empty anyway.

tests/indent: add skeletons for testing tokens and parser symbols

The constants that were previously defined in indent_codes.h were a wild
mixture of tokens from the lexer and symbols on the parser stack. They
were split into separate types starting at indent.h 1.49 from 2021-10-25
and finishing at 1.73 from 2021-10-31.

To match the tests with the new token names, the old tests need to be
migrated to the newly added tests. This will take some time so first
add the skeletons and migrate them in smaller steps, cleaning them up
and extending them on the way.

indent: remove FreeBSD IDs

Most of the IDs were empty anyway.

tests/indent: add skeletons for testing tokens and parser symbols

The constants that were previously defined in indent_codes.h were a wild
mixture of tokens from the lexer and symbols on the parser stack. They
were split into separate types starting at indent.h 1.49 from 2021-10-25
and finishing at 1.73 from 2021-10-31.

To match the tests with the new token names, the old tests need to be
migrated to the newly added tests. This will take some time so first
add the skeletons and migrate them in smaller steps, cleaning them up
and extending them on the way.