Sundry amendments to branch scratch/accurate-warning-pos.

Sundry amendments to branch scratch/accurate-warning-pos.

* src/lisp.h (symbols-with-pos-enabled, print-symbols-bare)
* src/data.c (syms-of-data)
* src/print.c (print_vectorlike, syms_of_print): Remove the leading V from
these variable names, and make them DEFVAR_BOOLs.

* src/keyboard.c (recursive_edit_1): bind symbols-with-pos-enabled and
print-symbols-bare to nil.

* lisp/emacs-lisp/bytecomp.el (compile-defun): Bind symbols-with-pos-enabled
to t around calls to the reader.  Call read-positioning-symbols
unconditionally (rather than read).
(byte-compile-from-buffer): Call read-positioning-symbols unconditionally
(rather than read).
(byte-compile-annotate-call-tree): Make local variables containing the values
of byte-compile-current-form and (car form) stripped of symbol positions, so
that the call tree functions function without having to bind
symbols-with-pos-enabled.