Change watchpoint_exp_is_const to return bool

I noticed that watchpoint_exp_is_const should return bool; this patch
implements this change.

gdb/ChangeLog
2020-11-21  Tom Tromey  <tom@tromey.com>

	* breakpoint.c (watchpoint_exp_is_const): Return bool.

2 files changed, 8 insertions, 4 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 4663f56..3d516df 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2020-11-21  Tom Tromey  <tom@tromey.com>
+
+	* breakpoint.c (watchpoint_exp_is_const): Return bool.
+
 2020-11-20  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* unittests/gmp-utils-selftests.c (gdb_mpz_read_all_from_small):
diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index 27324a0..61fbc3b 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -10084,7 +10084,7 @@ break_range_command (const char *arg, int from_tty)
     some constant expressions and in such case still falsely return
     zero.  */
 
-static int
+static bool
 watchpoint_exp_is_const (const struct expression *exp)
 {
   int i = exp->nelts;
@@ -10177,7 +10177,7 @@ watchpoint_exp_is_const (const struct expression *exp)
 	    if (SYMBOL_CLASS (s) != LOC_BLOCK
 		&& SYMBOL_CLASS (s) != LOC_CONST
 		&& SYMBOL_CLASS (s) != LOC_CONST_BYTES)
-	      return 0;
+	      return false;
 	    break;
 	  }
 
@@ -10185,11 +10185,11 @@ watchpoint_exp_is_const (const struct expression *exp)
 	   the optimistic approach here: If we don't know something,
 	   then it is not a constant.  */
 	default:
-	  return 0;
+	  return false;
 	}
     }
 
-  return 1;
+  return true;
 }
 
 /* Watchpoint destructor.  */