PR gdb/1914

	PR gdb/1914
	* fork-child.c (fork_inferior): Don't call
	solib_create_inferior_hook.
	* infcmd.c (post_create_inferior): Call solib_add,
	solib_create_inferior_hook, and re_enable_breakpoints_in_shlibs.
	(attach_command): Don't call solib_add or
	re_enable_breakpoints_in_shlibs.  Call post_create_inferior
	instead.
	* remote.c (remote_open_1): Don't call solib_create_inferior_hook
	or observer_notify_inferior_created.  Call post_create_inferior
	instead.
	* corelow.c: Don't include "observer.h".
	(solib_add_stub): Deleted.
	(core_open): Don't call observer_notify_inferior_created or
	solib_add_stub.  Call post_create_inferior instead.
	* inf-ptrace.c: Don't include "observer.h".
	(inf_ptrace_attach): Don't call observer_notify_inferior_created.
	* inf-ttrace.c: Don't include "observer.h".
	(inf_ttrace_attach): Don't call observer_notify_inferior_created.
	* inferior.h (solib_create_inferior_hook): Remove redundant
	prototype.
	* inftarg.c: Don't include "observer.h".
	(child_attach): Don't call observer_notify_inferior_created.
	* Makefile.in: Update dependencies.