This commit is the result of running the gdb/copyright.py script,
which automated the update of the copyright year range for all
source files managed by the GDB project to be updated to include
year 2023.
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.
For the avoidance of doubt, all changes in this commits were
performed by the script.
The following patches wants to change gdb_fopen_cloexec and
gdb_mkostemp_cloexec to return a scoped_fd. Doing this causes a cyclic
include between scoped_fd.h and filestuff.h, that both want to include
each other. scoped_fd.h includes filestuff.h because of the
scoped_fd::to_file method's return value. filestuff.h would then
include scoped_fd.h for gdb_fopen_cloexec's and gdb_mkostemp_cloexec's
return values.
To fix that, move gdb_file_up to its own file, gdb_file.h.
Change-Id: Ic82a48914b2aacee8f14af535b7469245f88b93d