[llvm-branch-commits] [MemProf] Make Test work with Internal Shell (PR #165146)

[Aiden Grossman via llvm-branch-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/165146

There is one test that uses a subshell to generate a long path name.
Replace it with a python invocation and a readfile substitution. This
helps move compiler-rt over to lit's internal shell.