There are somewhat common, reasonable and legitimate use cases for a
dependency to provide data files installed to /usr which are used as
command inputs. When getting a dependency from a subproject, however,
the attempt to directly construct an input file from a subproject
results in a sandbox violation. This means not all dependencies can be
wrapped as a subproject.
One example is wayland-protocols XML files which get scanned and used to
produce C source files.
Teach Meson to recognize when a string path is the result of fetching a
dep.get_variable(), and special case this to be exempt from subproject
violations.
A requirement of this is that the file must be installed by
install_data() or install_subdir() because otherwise it is not actually
representative of what a pkg-config dependency would provide.
This is the final refactoring for extracting the bultin object
logic out of Interpreterbase. I decided to do both arrays and
dicts in one go since splitting it would have been a lot more
confusing.
Another commit in my quest to rid InterpreterBase from all higher
level object processing logic.
Additionally, there is a a logic change here, since `str.join` now
uses varargs and can now accept more than one argument (and supports
list flattening).