This change ony concerns directives that appear in the document body.
The guidelines for inserting version directives:
* Baseline version is CMake 3.0, i.e. directives start at 3.1.
* Always use `.. versionadded::` directive, avoid ad-hoc version
references. Exception: policy pages.
* For new command signatures, put `versionadded` on a separate line
after the signature.
* For a group of new signatures in a new document section,
a single version note at the beginning of the section is sufficient.
* For new options, put `versionadded` on a separate line before
option description.
* If all the option descriptions in the list are short one-liners,
it's fine to put `versionadded` on the same line as the description.
* If multiple option descriptions in close proximity would have
the same ..versionadded directive, consider adding a single
directive after the list, mentioning all added options.
* For compact value lists and sub-option lists, put a single
`versionadded` directive after the list mentioning all additions.
* When a change is described in a single paragraph, put
`versionadded` into that paragraph.
* When only part of the paragraph has changed, separate the changed
part if it doesn't break the flow. Otherwise, write a follow-up
clarification paragraph and apply version directive to that.
* When multiple version directives are close by, order earlier
additions before later additions.
* Indent related lists and code blocks to include them in the scope
of `versionadded` directive.
Issue: #19715
Both set_source_files_properties() and set_property(SOURCE) now accept
two new optional arguments: DIRECTORY and TARGET_DIRECTORY.
The DIRECTORY option takes a list of relative or absolute paths
pointing to processed source directories (add_subdirectory was
already called on them).
These paths specify directory scopes where the source file properties
will be set. Previously the scope was always the currently processed
source directory.
Similarly TARGET_DIRECTORY takes a list of targets, whose source
directories will be used as the list of scopes where to set the
source file properties.
get_property() and get_source_file_property() also get the same
new arguments, except only one value can be specified instead
of a list.
Fixes: #20128
