fix for UnsupportedOperationException

	at org.eclipse.jdt.groovy.core.util.IntersectionType.putNodeMetaData(IntersectionType.java:155)
	at org.eclipse.jdt.groovy.core.util.GroovyUtils.implementsTrait(GroovyUtils.java:456)
	at org.eclipse.jdt.groovy.search.SimpleTypeLookup.findDeclaration(SimpleTypeLookup.java:753)
	at org.eclipse.jdt.groovy.search.SimpleTypeLookup.findTypeForNameWithKnownObjectExpression(SimpleTypeLookup.java:361)
	at org.eclipse.jdt.groovy.search.SimpleTypeLookup.findType(SimpleTypeLookup.java:244)
	at org.eclipse.jdt.groovy.search.SimpleTypeLookup.lookupType(SimpleTypeLookup.java:98)
	at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.lookupExpressionType(TypeInferencingVisitorWithRequestor.java:2992)
	at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.handleSimpleExpression(TypeInferencingVisitorWithRequestor.java:2177)
	at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.handleSimpleExpression(TypeInferencingVisitorWithRequestor.java:2182)
	at org.eclipse.jdt.groovy.search.TypeInferencingVisitorWithRequestor.visitConstantExpression(TypeInferencingVisitorWithRequestor.java:1096)
	at org.codehaus.groovy.ast.expr.ConstantExpression.visit(ConstantExpression.java:88)

Author: eric-milles

base-test/org.eclipse.jdt.groovy.core.tests.builder/src/org/eclipse/jdt/core/groovy/tests/search/InferencingTests.java

@@ -4206,7 +4206,7 @@ public void testInstanceOf10() {
         String contents =
             "def val = new Object()\n" +
             "if (val instanceof Number || val instanceof CharSequence) {\n" +
-            "  println val\n" +
+            "  println val.size()\n" +
             "}\n" +
             "val";
 

base/org.eclipse.jdt.groovy.core/src/org/eclipse/jdt/groovy/core/util/GroovyUtils.java

@@ -441,6 +441,10 @@ public static Expression getTraitFieldExpression(MethodCallExpression call) {
     }
 
     public static boolean implementsTrait(ClassNode concreteType) {
+        if (concreteType instanceof IntersectionType it) {
+            return it.types.stream().allMatch(GroovyUtils::implementsTrait);
+        }
+
         Boolean it = concreteType.getNodeMetaData(Traits.class);
         if (it != null) return it.booleanValue();