SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
Some of the device names can be ambiguous and require fully or partly
qualifying the name (e.g. IOS::HLE::FS::) in a somewhat verbose way.
Additionally, insufficiently qualified names are prone to breaking.
Consider the example of IOS::HLE::FS:: (namespace) and
IOS::HLE::Device::FS (class). If we use FS::Foo in a file that doesn't
know about the class, everything will work fine. However, as soon as
Device::FS is declared via a header include or even just forward
declared, that code will cease to compile because FS:: now resolves
to Device::FS if FS::Foo was used in the Device namespace.
It also leads to having to write IOS::ES:: to access ES types and
utilities even for code that is already under the IOS namespace.
The fix for this is simple: rename the device classes and give them
a "device" suffix in their names if the existing ones may be ambiguous.
This makes it clear whether we're referring to the device class or to
something else.
This is not any longer to type, considering it lets us get rid of the
Device namespace, which is now wholly unnecessary.
There are no functional changes in this commit.
A future commit will fix unnecessarily qualified names.