Boolify breakpoint::explains_signal

This changes breakpoint::explains_signal to return bool.

gdb/break-catch-sig.c

@@ -51,7 +51,7 @@ struct signal_catchpoint : public breakpoint
   bool print_one (struct bp_location **) override;
   void print_mention () override;
   void print_recreate (struct ui_file *fp) override;
-  int explains_signal (enum gdb_signal) override;
+  bool explains_signal (enum gdb_signal) override;
 
   /* Signal numbers used for the 'catch signal' feature.  If no signal
      has been specified for filtering, it is empty.  Otherwise,
@@ -297,10 +297,10 @@ signal_catchpoint::print_recreate (struct ui_file *fp)
 
 /* Implement the "explains_signal" method for signal catchpoints.  */
 
-int
+bool
 signal_catchpoint::explains_signal (enum gdb_signal sig)
 {
-  return 1;
+  return true;
 }
 
 /* Create a new signal catchpoint.  TEMPFLAG is true if this should be

gdb/breakpoint.c

@@ -9716,15 +9716,15 @@ watchpoint::print_recreate (struct ui_file *fp)
 
 /* Implement the "explains_signal" method for watchpoints.  */
 
-int
+bool
 watchpoint::explains_signal (enum gdb_signal sig)
 {
   /* A software watchpoint cannot cause a signal other than
      GDB_SIGNAL_TRAP.  */
   if (type == bp_watchpoint && sig != GDB_SIGNAL_TRAP)
-    return 0;
+    return false;
 
-  return 1;
+  return true;
 }
 
 struct masked_watchpoint : public watchpoint

gdb/breakpoint.h

@@ -721,9 +721,9 @@ struct breakpoint
 
   /* Return true if this breakpoint explains a signal.  See
      bpstat_explains_signal.  */
-  virtual int explains_signal (enum gdb_signal)
+  virtual bool explains_signal (enum gdb_signal)
   {
-    return 1;
+    return true;
   }
 
   /* Called after evaluating the breakpoint's condition,
@@ -882,7 +882,7 @@ struct watchpoint : public breakpoint
   enum print_stop_action print_it (struct bpstat *bs) override;
   void print_mention () override;
   void print_recreate (struct ui_file *fp) override;
-  int explains_signal (enum gdb_signal) override;
+  bool explains_signal (enum gdb_signal) override;
 
   /* String form of exp to use for displaying to the user (malloc'd),
      or NULL if none.  */