Revert "[MemProf] Memprof profile matching and annotation"

This reverts commit a212d8da, and follow
on fixes 0cd6763f,
e9ff53d4, and
37c6a25e.

After re-reading the documentation for hash_combine, I don't think this
is the appropriate hash function to use for computing the hash to use as
a stack id in the metadata, since it is not guaranteed to produce stable
values across executions. I have not hit this problem, but plan to
switch to using an MD5 hash. I am hitting an issue with one of the bots
(https://lab.llvm.org/buildbot/#/builders/171/builds/20732)
where the values produced are only the lower 32 bits of the expected
hash values, however, which I assume is related to the implementation of
hash_combine and hash_code.

I believe I fixed all of the other bot failures with the follow on fixes,
which I'll merge into the new version before reapplying.