Revert "[llvm-profdata] Speed up merging by using a thread pool"

This reverts commit r275921. It broke the ppc64be bot:

  http://lab.llvm.org:8011/builders/clang-ppc64be-linux-multistage/builds/3537

I'm not sure why it broke, but based on the output, it looks like an
off-by-one (one profile left un-merged).

llvm-svn: 275937

1 files changed, 0 insertions, 8 deletions

diff --git a/llvm/lib/ProfileData/InstrProfWriter.cpp b/llvm/lib/ProfileData/InstrProfWriter.cpp
index 7fabcdbff63..e25299ef670 100644
--- a/llvm/lib/ProfileData/InstrProfWriter.cpp
+++ b/llvm/lib/ProfileData/InstrProfWriter.cpp
@@ -182,14 +182,6 @@ Error InstrProfWriter::addRecord(InstrProfRecord &&I, uint64_t Weight) {
   return Dest.takeError();
 }
 
-Error InstrProfWriter::mergeRecordsFromWriter(InstrProfWriter &&IPW) {
-  for (auto &I : IPW.FunctionData)
-    for (auto &Func : I.getValue())
-      if (Error E = addRecord(std::move(Func.second), 1))
-        return E;
-  return Error::success();
-}
-
 bool InstrProfWriter::shouldEncodeData(const ProfilingData &PD) {
   if (!Sparse)
     return true;