Add missing messages 'isBoolean' and 'asBoolean'.

Author: fangerer

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/ints/PInt.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2018, Oracle and/or its affiliates.
+ * Copyright (c) 2017, 2019, Oracle and/or its affiliates.
  * Copyright (c) 2013, Regents of the University of California
  *
  * All rights reserved.
@@ -27,9 +27,13 @@
 
 import java.math.BigInteger;
 
+import com.oracle.graal.python.PythonLanguage;
 import com.oracle.graal.python.builtins.objects.object.PythonBuiltinObject;
 import com.oracle.graal.python.builtins.objects.type.LazyPythonClass;
+import com.oracle.graal.python.runtime.PythonContext;
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
+import com.oracle.truffle.api.dsl.Cached.Shared;
+import com.oracle.truffle.api.dsl.CachedContext;
 import com.oracle.truffle.api.interop.InteropLibrary;
 import com.oracle.truffle.api.interop.UnsupportedMessageException;
 import com.oracle.truffle.api.library.CachedLibrary;
@@ -59,6 +63,23 @@ public boolean isZero() {
         return value.equals(BigInteger.ZERO);
     }
 
+    @ExportMessage
+    public boolean isBoolean(
+                    @Shared("context") @CachedContext(PythonLanguage.class) PythonContext context) {
+        return this == context.getCore().getTrue() || this == context.getCore().getFalse();
+    }
+
+    @ExportMessage
+    public boolean asBoolean(
+                    @Shared("context") @CachedContext(PythonLanguage.class) PythonContext context) throws UnsupportedMessageException {
+        if (this == context.getCore().getTrue()) {
+            return true;
+        } else if (this == context.getCore().getFalse()) {
+            return false;
+        }
+        throw UnsupportedMessageException.create();
+    }
+
     @ExportMessage
     @SuppressWarnings("static-method")
     public boolean isNumber() {