Resolve "intentional" memory leaks in RAJA memory pool use

[rhornung67]

According to @MrBurmark there are some intentional memory leaks in RAJA for memory pools. They cause sort tests to fail when address sanitizer is enabled. Can they be removed?

[MrBurmark]

I'll have to look at this again, the memory may be cleaned up after main. I know that any memory allocated through cuda and hip is not freed because the cleanup is done after main.

[rhornung67]

This showed up when Adrien was trying to set up asan for clang with OpenMP enabled.

If we free all RAJA memory pools using atexit(), or something else like it, asan will still complain, right?