Entry not found error for file in compile_commands.json

[Colengms]

It looks like we gate parsing of a compile_commands.json entries based on whether the file exists on disk. So, if the file is later created, we report an error that the entry was not found, despite it being present.

"test8.cpp" not found in "${workspaceFolder}\build\compile_commands.json". 'includePath' from c_cpp_properties.json in folder 'test2' will be used for this file instead.