Fix PR 20345 - call_function_by_hand_dummy: Assertion `tp->thread_fsm == &sm->thread_...

Fix PR 20345 - call_function_by_hand_dummy: Assertion `tp->thread_fsm == &sm->thread_fsm' failed

If you run an infcall from the command line, and immediately after run
some other command, GDB incorrectly processes the other command before
the infcall finishes.

The problem is that the fix for PR gdb/20418 (Problems with
synchronous commands and new-ui, git 3eb7562a983b) moved the
add_file_handler/delete_file_handler calls out of
target_terminal_$foo, and missed adjusting the infcall code.

gdb/ChangeLog:
2016-09-28  Pedro Alves  <palves@redhat.com>

	* infcall.c (run_inferior_call): Remove input from the event
	loop while running the infcall.

gdb/testsuite/ChangeLog:
2016-09-28  Pedro Alves  <palves@redhat.com>

	* gdb.base/infcall-input.c: New file.
	* gdb.base/infcall-input.exp: New file.