More True/False changes.

src/core/Failure.pm

@@ -16,10 +16,10 @@ my class Failure {
     # but obscure problems prevent us from making Mu.defined
     # a multi. See http://irclog.perlgeek.de/perl6/2011-06-28#i_4016747
     method defined() {
-        $!handled =1 if nqp::p6bool(pir::repr_defined__IP(self));
-        0.Bool;
+        $!handled =1 if pir::repr_defined__IP(self);
+        Bool::False;
     }
-    multi method Bool(Failure:D:) { $!handled = 1; 0.Bool; }
+    multi method Bool(Failure:D:) { $!handled = 1; Bool::False; }
 
     method Int(Failure:D:) { $!handled ?? 0 !! $!exception.rethrow; }
     method Num(Failure:D:) { $!handled ?? 0e0 !! $!exception.rethrow; }

src/core/Int.pm

@@ -2,8 +2,7 @@ class Rat { ... }
 
 my class Int {
     method Bool() {
-        nqp::p6bool(
-            nqp::isne_i(nqp::unbox_i(self), nqp::unbox_i(0)))
+        nqp::p6bool(nqp::isne_i(nqp::unbox_i(self), 0))
     }
 
     method Int() { self }

src/core/ListIter.pm

@@ -62,7 +62,7 @@ my class ListIter {
           ?? nqp::istype(nqp::atpos($!rest, 0), Iterable)
              && nqp::atpos($!rest,0).infinite
              || Mu
-          !! 0.Bool
+          !! Bool::False
     }
 
     method iterator() { self }

src/core/Mu.pm

@@ -124,11 +124,11 @@ my class Mu {
         while $i < +@mro {
             my $obj = @mro[$i];
             if $obj.HOW.name($obj) eq $name {
-                return nqp::p6bool(1);
+                return Bool::True;
             }
             $i++;
         }
-        nqp::p6bool(0)
+        Bool::False
     }
 
     method does(Mu $type) {

src/core/operators.pm

@@ -11,7 +11,7 @@ sub SEQUENCE($left, $right, :$exclude_end) {
     my @right := ($right,).list;
     my $endpoint = @right.shift;
     my $infinite = $endpoint ~~ Whatever;
-    $endpoint = 0.Bool if $infinite;
+    $endpoint = Bool::False if $infinite;
     my $tail := ().list;
 
     my sub generate($code) {