GenericKernelTy has a pointer to the name that was used to create it.
However, the name passed in as an argument may not outlive the kernel.
Instead, GenericKernelTy now contains a std::string, and copies the
name into there.

AMD treats this value as a string, so for consistency require this in
NVIDIA as well. This shouldn't change the output of the
`llvm-offload-device-info` tool, but does fix an issue in liboffload
when it tries to query the version.

Summary:
There's a new one called the AIE (AI Engine). We could handle this, but
since we don't use it currently I'm just making it future-proof. Adding
the AIE check would require checking the HSA version which isn't
worthwhile just yet.

This allows removal of a specific Image from a Device, rather than
requiring all image data to outlive the device they were created for.

This is required for `ol_program_handle_t`s, which now specify the
lifetime of the buffer used to create the program.

Previously, if a binary failed to load due to failures when jit
compiling, the function would return success with nullptr. Now it
returns a new plugin error, `COMPILE_FAILURE`.

Rather than being "stringly typed", store values as a std::variant that
can hold various types. This means that liboffload doesn't have to do
any string parsing for integer/bool device info keys.

Previously, device info was returned as a queue with each element having
a "Level" field indicating its nesting level. This replaces this queue
with a more traditional tree-like structure.

This should not result in a change to the output of
`llvm-offload-device-info`.

This pull request fixes coverage mapping on GPU targets. 

- It adds an address space cast to the coverage mapping generation pass.
- It reads the profiled function names from the ELF directly. Reading it
from public globals was causing issues in cases where multiple
device-code object files are linked together.

This isn't required when building with Ninja, but with the Makefile
generator these directories don't get implicitly created.