This commit moves internal_warning and internal_vwarning into
common/errors.[ch].
gdb/ChangeLog:
* common/errors.h (internal_warning): New declaration.
(internal_vwarning): Likewise.
* common/errors.c (internal_warning): New function.
* utils.h (internal_warning): Don't declare.
(internal_vwarning): Likewise.
* utils.c (internal_warning): Removed.
gdb/gdbserver/ChangeLog:
* utils.c (internal_vwarning): New function.