[memprof] Add MemProfReader::takeMemProfData (#116769)

This patch adds MemProfReader::takeMemProfData, a function to return
the complete MemProf profile from the reader.  We can directly pass
its return value to InstrProfWriter::addMemProfData without having to
deal with the indivual components of the MemProf profile.  The new
function is named "take", but it doesn't do std::move yet because of
type differences (DenseMap v.s. MapVector).

The end state I'm trying to get to is roughly as follows:

- MemProfReader accepts IndexedMemProfData as a parameter as opposed
  to the three individual components (frames, call stacks, and
  records).

- MemProfReader keeps IndexedMemProfData as a class member without
  decomposing it into its individual components.

- MemProfReader returns IndexedMemProfData like:

  IndexedMemProfData takeMemProfData() {
    return std::move(MemProfData);
  }

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/ProfileData/InstrProfWriter.cpp b/llvm/lib/ProfileData/InstrProfWriter.cpp
index 87a538f..a1341d0 100644
--- a/llvm/lib/ProfileData/InstrProfWriter.cpp
+++ b/llvm/lib/ProfileData/InstrProfWriter.cpp
@@ -370,7 +370,8 @@ bool InstrProfWriter::addMemProfData(memprof::IndexedMemProfData Incoming,
       if (addMemProfCallStack(CSId, CS, Warn))
         return false;
 
-  if (MemProfData.Records.empty())
+  // Add one record at a time if randomization is requested.
+  if (MemProfData.Records.empty() && !MemprofGenerateRandomHotness)
     MemProfData.Records = std::move(Incoming.Records);
   else
     for (const auto &[GUID, Record] : Incoming.Records)