Add interface for JIT code generation.

* NEWS: Announce JIT interface.
	* Makefile.in (SFILES): Add jit.c.
	(HFILES_NO_SRCDIR): Add jit.h.
	(COMMON_OBS): Add jit.o.
	* jit.c: New file.
	* jit.h: New file.
	* breakpoint.h (enum bptype): Add bp_jit_event to enum.
	* breakpoint.c:
	(update_breakpoints_after_exec): Delete jit breakpoints after exec.
	(bpstat_what): Update event table for bp_jit_event.
	(print_it_typical): Added case for bp_jit_event.
	(print_one_breakpoint_location): Added case for bp_jit_event.
	(allocate_bp_location): Added case for bp_jit_event.
	(mention): Added case for bp_jit_event.
	(delete_command): Added case for bp_jit_event.
	(breakpoint_re_set_one): Added case for bp_jit_event.
	(breakpoint_re_set): Added call to jit_inferior_created_hook.
	(create_jit_event_breakpoint): New.
	* infrun.c (handle_inferior_event): Add handler for jit event.
	(follow_exec): Add call to jit_inferior_created_hook.
	* doc/gdb.texinfo: Add chapter on JIT interface.

gdb/breakpoint.h

@@ -120,6 +120,9 @@ enum bptype
     bp_catchpoint,
 
     bp_tracepoint,
+
+    /* Event for JIT compiled code generation or deletion.  */
+    bp_jit_event,
   };
 
 /* States of enablement of breakpoint. */
@@ -554,6 +557,9 @@ enum bpstat_what_main_action
        keep checking.  */
     BPSTAT_WHAT_CHECK_SHLIBS,
 
+    /* Check for new JITed code.  */
+    BPSTAT_WHAT_CHECK_JIT,
+
     /* This is just used to keep track of how many enums there are.  */
     BPSTAT_WHAT_LAST
   };
@@ -865,6 +871,9 @@ extern void mark_breakpoints_out (void);
 
 extern void make_breakpoint_permanent (struct breakpoint *);
 
+extern struct breakpoint *create_jit_event_breakpoint (struct gdbarch *,
+                                                       CORE_ADDR);
+
 extern struct breakpoint *create_solib_event_breakpoint (struct gdbarch *,
 							 CORE_ADDR);