Steps for generating a profile-guided optimization (PGO) build:
1. Select PGInstrument build config and rebuild solution.
2. Run the training program (e.g. x64\PGInstrument\StringTable2BenchmarkExe.exe)
3. Run update-pgd.bat.
4. Select PGOptimize build config and *build* solution. Don't select
rebuild, as it deletes all the .pgd files generated by the PGInstrument
phase and generally breaks everything.