I spotted a few misplaced entries in the ChangeLog-2019 entries, and
went on to fix them.
Looking around I saw a good number of other entries in other years.
Then OCD got the best of me and I fixed them all.
Also fixes cases of wrong paths in entries, like "* gdb/foo.c" instead
of "* foo.c".
Abstract the functionality of iterating over mapped memory
regions into a general purpose iterator function.
* procfs.c (iterate_over_mappings): New function, general purpose
iterator for memory sections.
(proc_iterate_over_mappings): Reimplement using iterate_over_mappings.
(solib_mappings_callback): New function, callback for above.
(info_proc_mappings): Reimpliment using iterate_over_mappings.
(info_mappings_callback): New function, callback for above.
* procfs.c (proc_set_watchpoint): Add cast to suppress warning.
