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.
Greatly simplifies the overall interface when it comes to compiling
shaders. Also allows getting rid of a std::string overload of the same
name. Now std::string and const char* both go through the same function.
Depending on which constructor is invoked, m_id or m_compute_program_id
can end up in an uninitialized state. We should ensure that the object
is completely initialized to something deterministic regardless of the
constructor taken.