Java: Add isImplict predicate to CompilationUnit and Class

Author: IdrissRio

java/ql/lib/semmle/code/java/CompilationUnit.qll

@@ -33,5 +33,13 @@ class CompilationUnit extends Element, File {
    */
   Module getModule() { cumodule(this, result) }
 
+  /**
+   * Holds if this compilation unit represents a compact source file.
+   * A compact source file contains an implicitly declared top-level class.
+   */
+  predicate isCompactSourceFile() {
+    exists(Class c | c.getCompilationUnit() = this and c.isImplicit())
+  }
+
   override string getAPrimaryQlClass() { result = "CompilationUnit" }
 }

java/ql/lib/semmle/code/java/Type.qll

@@ -699,6 +699,9 @@ class Class extends ClassOrInterface {
   /** Holds if this class is an anonymous class. */
   predicate isAnonymous() { isAnonymClass(this.getSourceDeclaration(), _) }
 
+  /** Holds if this class is an implicit class (compact source file). */
+  predicate isImplicit() { isImplicitClass(this.getSourceDeclaration()) }
+
   /**
    * Gets an annotation that applies to this class.
    *