Remove some includes of readline.h

Remove some includes of readline.h

I went through most of the spots that include readline.h and, when
appropriate, either removed the include or changed it to include
tilde.h.

Note that remote-sim.c and bsd-kvm.c could probably include tilde.h
instead, but I did not change these.  I think I can't build the
latter, and I didn't want to set up a sim build for the former.

Tested by rebuilding.

gdb/ChangeLog
2019-11-06  Tom Tromey  <tom@tromey.com>

	* tui/tui-interp.c: Don't include readline.h.
	* tui/tui-hooks.c: Don't include readline.h.
	* symmisc.c: Include tilde.h, not readline.h.
	* symfile.c: Include tilde.h, not readline.h.
	* source.c: Include tilde.h, not readline.h.
	* solib.c: Include tilde.h, not readline.h.
	* psymtab.c: Include tilde.h, not readline.h.
	* exec.c: Include tilde.h, not readline.h.
	* corelow.c: Include tilde.h, not readline.h.
	* cli/cli-dump.c: Include tilde.h, not readline.h.
	* cli/cli-cmds.c: Don't include readline.h.

Change-Id: I60487a190c43128b800ef77517d1ab42957571d7