Add testbed reproducing diagnostic pull on a saved unsaved-but-named buffer#1798

dbaeumer with Copilot wants to merge 3 commits into

mainmicrosoft/vscode-languageserver-node:mainfrom

copilot/diagnostics-requested-after-saving-buffermicrosoft/vscode-languageserver-node:copilot/diagnostics-requested-after-saving-bufferCopy head branch name to clipboard