Do not include py-ref.h in most files

py-ref.h can really only be included from a specific spot in
python-internal.h.  The other includes are not useful, and cause
compilation errors if the includes are ever sorted.  So, remove these
includes.

Arguably, py-ref.h should simply not be a separate header.

gdb/ChangeLog
2019-01-22  Tom Tromey  <tom@tromey.com>

	* python/py-arch.c: Do not include py-ref.h.
	* python/py-bpevent.c: Do not include py-ref.h.
	* python/py-cmd.c: Do not include py-ref.h.
	* python/py-continueevent.c: Do not include py-ref.h.
	* python/py-event.h: Do not include py-ref.h.
	* python/py-evtregistry.c: Do not include py-ref.h.
	* python/py-finishbreakpoint.c: Do not include py-ref.h.
	* python/py-frame.c: Do not include py-ref.h.
	* python/py-framefilter.c: Do not include py-ref.h.
	* python/py-function.c: Do not include py-ref.h.
	* python/py-infevents.c: Do not include py-ref.h.
	* python/py-linetable.c: Do not include py-ref.h.
	* python/py-objfile.c: Do not include py-ref.h.
	* python/py-param.c: Do not include py-ref.h.
	* python/py-prettyprint.c: Do not include py-ref.h.
	* python/py-progspace.c: Do not include py-ref.h.
	* python/py-symbol.c: Do not include py-ref.h.
	* python/py-symtab.c: Do not include py-ref.h.
	* python/py-type.c: Do not include py-ref.h.
	* python/py-unwind.c: Do not include py-ref.h.
	* python/py-utils.c: Do not include py-ref.h.
	* python/py-value.c: Do not include py-ref.h.
	* python/py-varobj.c: Do not include py-ref.h.
	* python/py-xmethods.c: Do not include py-ref.h.
	* python/python.c: Do not include py-ref.h.
	* varobj.c: Do not include py-ref.h.

gdb/python/py-arch.c

@@ -22,7 +22,6 @@
 #include "arch-utils.h"
 #include "disasm.h"
 #include "python-internal.h"
-#include "py-ref.h"
 
 typedef struct arch_object_type_object {
   PyObject_HEAD

gdb/python/py-bpevent.c

@@ -19,7 +19,6 @@
 
 #include "defs.h"
 #include "py-stopevent.h"
-#include "py-ref.h"
 
 /* Create and initialize a BreakpointEvent object.  This acquires new
    references to BREAKPOINT_LIST and FIRST_BP.  */

gdb/python/py-cmd.c

@@ -27,7 +27,6 @@
 #include "cli/cli-decode.h"
 #include "completer.h"
 #include "language.h"
-#include "py-ref.h"
 
 /* Struct representing built-in completion types.  */
 struct cmdpy_completer

gdb/python/py-continueevent.c

@@ -19,7 +19,6 @@
 
 #include "defs.h"
 #include "py-event.h"
-#include "py-ref.h"
 #include "gdbthread.h"
 
 /* Create a gdb.ContinueEvent event.  gdb.ContinueEvent is-a

gdb/python/py-event.h

@@ -24,7 +24,6 @@
 #include "command.h"
 #include "python-internal.h"
 #include "inferior.h"
-#include "py-ref.h"
 
 /* Declare all event types.  */
 #define GDB_PY_DEFINE_EVENT_TYPE(name, py_name, doc, base) \

gdb/python/py-evtregistry.c

@@ -20,7 +20,6 @@
 #include "defs.h"
 #include "command.h"
 #include "py-events.h"
-#include "py-ref.h"
 
 events_object gdb_py_events;
 

gdb/python/py-finishbreakpoint.c

@@ -30,7 +30,6 @@
 #include "inferior.h"
 #include "block.h"
 #include "location.h"
-#include "py-ref.h"
 
 /* Function that is called when a Python finish bp is found out of scope.  */
 static const char outofscope_func[] = "out_of_scope";

gdb/python/py-frame.c

@@ -28,7 +28,6 @@
 #include "symfile.h"
 #include "objfiles.h"
 #include "user-regs.h"
-#include "py-ref.h"
 
 typedef struct {
   PyObject_HEAD

gdb/python/py-framefilter.c

@@ -30,7 +30,6 @@
 #include "demangle.h"
 #include "mi/mi-cmds.h"
 #include "python-internal.h"
-#include "py-ref.h"
 #include "common/gdb_optional.h"
 
 enum mi_print_types

gdb/python/py-function.c

@@ -27,7 +27,6 @@
 #include "completer.h"
 #include "expression.h"
 #include "language.h"
-#include "py-ref.h"
 
 extern PyTypeObject fnpy_object_type
     CPYCHECKER_TYPE_OBJECT_FOR_TYPEDEF ("PyObject");

gdb/python/py-infevents.c

@@ -19,7 +19,6 @@
 
 #include "defs.h"
 #include "py-event.h"
-#include "py-ref.h"
 
 /* Construct either a gdb.InferiorCallPreEvent or a
    gdb.InferiorCallPostEvent. */

gdb/python/py-linetable.c

@@ -19,7 +19,6 @@
 
 #include "defs.h"
 #include "python-internal.h"
-#include "py-ref.h"
 
 typedef struct {
   PyObject_HEAD

gdb/python/py-objfile.c

@@ -24,7 +24,6 @@
 #include "language.h"
 #include "build-id.h"
 #include "symtab.h"
-#include "py-ref.h"
 
 typedef struct
 {

gdb/python/py-param.c

@@ -27,7 +27,6 @@
 #include "completer.h"
 #include "language.h"
 #include "arch-utils.h"
-#include "py-ref.h"
 
 /* Parameter constants and their values.  */
 struct parm_constant

gdb/python/py-prettyprint.c

@@ -25,7 +25,6 @@
 #include "extension-priv.h"
 #include "python.h"
 #include "python-internal.h"
-#include "py-ref.h"
 
 /* Return type of print_string_repr.  */
 

gdb/python/py-progspace.c

@@ -24,7 +24,6 @@
 #include "objfiles.h"
 #include "language.h"
 #include "arch-utils.h"
-#include "py-ref.h"
 #include "solib.h"
 #include "block.h"
 

gdb/python/py-symbol.c

@@ -23,7 +23,6 @@
 #include "symtab.h"
 #include "python-internal.h"
 #include "objfiles.h"
-#include "py-ref.h"
 
 typedef struct sympy_symbol_object {
   PyObject_HEAD

gdb/python/py-symtab.c

@@ -24,7 +24,6 @@
 #include "python-internal.h"
 #include "objfiles.h"
 #include "block.h"
-#include "py-ref.h"
 
 typedef struct stpy_symtab_object {
   PyObject_HEAD

gdb/python/py-type.c

@@ -28,7 +28,6 @@
 #include "language.h"
 #include "vec.h"
 #include "typeprint.h"
-#include "py-ref.h"
 
 typedef struct pyty_type_object
 {

gdb/python/py-unwind.c

@@ -28,7 +28,6 @@
 #include "regcache.h"
 #include "valprint.h"
 #include "user-regs.h"
-#include "py-ref.h"
 
 #define TRACE_PY_UNWIND(level, args...) if (pyuw_debug >= level)  \
   { fprintf_unfiltered (gdb_stdlog, args); }

gdb/python/py-utils.c

@@ -21,7 +21,6 @@
 #include "charset.h"
 #include "value.h"
 #include "python-internal.h"
-#include "py-ref.h"
 
 /* Converts a Python 8-bit string to a unicode string object.  Assumes the
    8-bit string is in the host charset.  If an error occurs during conversion,

gdb/python/py-value.c

@@ -29,7 +29,6 @@
 #include "python.h"
 
 #include "python-internal.h"
-#include "py-ref.h"
 
 /* Even though Python scalar types directly map to host types, we use
    target types here to remain consistent with the values system in

gdb/python/py-varobj.c

@@ -17,7 +17,6 @@
 #include "python-internal.h"
 #include "varobj.h"
 #include "varobj-iter.h"
-#include "py-ref.h"
 
 /* A dynamic varobj iterator "class" for python pretty-printed
    varobjs.  This inherits struct varobj_iter.  */

gdb/python/py-xmethods.c

@@ -26,7 +26,6 @@
 
 #include "python.h"
 #include "python-internal.h"
-#include "py-ref.h"
 
 static const char enabled_field_name[] = "enabled";
 static const char match_method_name[] = "match";

gdb/python/python.c

@@ -98,7 +98,6 @@ const struct extension_language_defn extension_language_python =
 #include "gdbthread.h"
 #include "interps.h"
 #include "event-top.h"
-#include "py-ref.h"
 #include "py-event.h"
 
 /* True if Python has been successfully initialized, false