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.
Various files were not including the relevant headers, or some funcs
were missing prototypes entirely, leading to mismatch between the
actual definition of the functions. Add includes to a few places and
fix the broken functions that are uncovered as a result. Fixing some
compile warnings (e.g. missing prototypes) often find real bugs.
This commits the result of running gdb/copyright.py as per our Start
of New Year procedure...
gdb/ChangeLog
Update copyright year range in copyright header of all GDB files.
