Imports of preprofile command

PathSynopsis
bufioPackage bufio implements buffered I/O. It wraps an io.Reader or io.Writer object, creating another object (Reader or Writer) that also implements the interface but provides buffering and some help for textual I/O.
cmd/internal/objabi
cmd/internal/pgoPackage pgo contains the compiler-agnostic portions of PGO profile handling.
cmd/internal/telemetry/counter
flagPackage flag implements command-line flag parsing.
fmtPackage fmt implements formatted I/O with functions analogous to C's printf and scanf.
logPackage log implements a simple logging package.
osPackage os provides a platform-independent interface to operating system functionality.