Re-add the xPPTRF routines (rename xPOTRF routines from #3123)#3229

andrew-platt merged 3 commits intoOpenFAST:rc-4.2.1OpenFAST/openfast:rc-4.2.1from

andrew-platt:f/xPPTRF_to_xPOTRFandrew-platt/openfast:f/xPPTRF_to_xPOTRFCopy head branch name to clipboard