This patch adds support for optional memory profile information to be
included with and indexed profile. The indexed profile header adds a new
field which points to the offset of the memory profile section (if
present) in the indexed profile. For users who do not utilize this
feature the only overhead is a 64-bit offset in the header.
The memory profile section contains (1) profile metadata describing the
information recorded for each entry (2) an on-disk hashtable containing
the profile records indexed via llvm::md5(function_name). We chose to
introduce a separate hash table instead of the existing one since the
indexing for the instrumented fdo hash table is based on a CFG hash
which itself is perturbed by memprof instrumentation.
I noticed this change and the one below are not in compiler-rt/include/profile/InstrProfData.inc, I assume these two files should be identical?