javacc-wrapper: Avoid replace for non existent parser files

This avoids errors like
[ERROR] [replaceregexp] The following file is missing: '.../pmd/pmd-javascript/target/generated-sources/javacc/net/sourceforge/pmd/lang/ecmascript5/ast/Ecmascript5ParserImpl.java'

javacc-wrapper.xml

@@ -19,6 +19,9 @@
 
          - lang-id: The language id, used in the conventional package names
 
+         - no-jjtree: true/false. Use true for CPD-only languages. Then a parser won't
+                      be generated. By default, a parser will be generated (and jjtree will be called).
+
          It also uses the following maven properties:
 
          - javacc.outputDirectory:  Directory in which to root the generated package tree
@@ -219,11 +222,11 @@
 
     </target>
 
-    <target name="cleanup-parser">
+    <target name="cleanup-parser" unless="jjtreeBuildNotRequired">
 
 
         <replace token="new Token()" value="token_source.input_stream.getTokenDocument().open()">
-            <fileset file="${parser-file}" />
+            <file name="${parser-file}" />
         </replace>
 
         <replaceregexp flags="g">
@@ -242,25 +245,25 @@
         <replaceregexp flags="g">
             <regexp pattern="\bJJT${parser-name}State\b" />
             <substitution expression="${ast-impl-package}.JjtreeBuilder&lt;${base-class-name}&gt;" />
-            <fileset file="${parser-file}" />
+            <file name="${parser-file}" />
         </replaceregexp>
 
         <replaceregexp flags="g">
             <regexp pattern="new ParseException\(token, exptokseq, tokenImage\);" />
             <substitution expression="new ParseException(token, exptokseq);" />
-            <fileset file="${parser-file}" />
+            <file name="${parser-file}" />
         </replaceregexp>
 
         <replaceregexp flags="g">
             <regexp pattern="throw new ParseException\(\);" />
             <substitution expression='throw net.sourceforge.pmd.util.AssertionUtil.shouldNotReachHere("consumetoken(-1) should have thrown");' />
-            <fileset file="${parser-file}" />
+            <file name="${parser-file}" />
         </replaceregexp>
 
         <replaceregexp>
             <regexp pattern="public interface"/>
             <substitution expression="interface"/>
-            <fileset file="${target-package-dir}/${parser-name}TreeConstants.java" />
+            <file name="${target-package-dir}/${parser-name}TreeConstants.java" />
         </replaceregexp>
 
     </target>
@@ -372,8 +375,8 @@
         <replaceregexp>
             <regexp pattern="package ${lang-ast-package};" />
             <substitution expression="\0${line.separator}${line.separator}import static ${lang-ast-package}.${token-constants-name}.*;" />
-            <fileset file="${tokenmgr-file}" />
-            <fileset file="${parser-file}" />
+            <file name="${tokenmgr-file}" />
+            <file name="${parser-file}" />
         </replaceregexp>
 
         <!-- Create constants file  -->
@@ -387,26 +390,26 @@
 public final class ${token-constants-name} \{${line.separator}
     private ${token-constants-name}() { /* Utility class */ }${line.separator}
 "/>
-            <fileset file="${token-constants-file}" />
+            <file name="${token-constants-file}" />
         </replaceregexp>
 
         <replaceregexp flags="g">
             <regexp pattern="/\*\* RegularExpression Id. \*/\R" />
             <substitution expression="public static final " />
-            <fileset file="${token-constants-file}" />
+            <file name="${token-constants-file}" />
         </replaceregexp>
 
         <replaceregexp flags="s">
             <regexp pattern="/\*\* End of File. \*/\R" />
             <substitution expression="public static final " />
-            <fileset file="${token-constants-file}" />
+            <file name="${token-constants-file}" />
         </replaceregexp>
 
         <!-- Lexical states are kept package-private -->
         <replaceregexp flags="g">
             <regexp pattern="/\*\* Lexical state. \*/\R" />
             <substitution expression="static final " />
-            <fileset file="${token-constants-file}" />
+            <file name="${token-constants-file}" />
         </replaceregexp>
 
         <replace>
@@ -438,7 +441,7 @@ public final class ${token-constants-name} \{${line.separator}
 
     private static final
 ]]>            </replacevalue>
-            <fileset file="${token-constants-file}" />
+            <file name="${token-constants-file}" />
         </replace>
 
         <replace>
@@ -449,19 +452,19 @@ public final class ${token-constants-name} \{${line.separator}
   /** Nams of the tokens, each index corresponds to a kind. See also {@link #describe(int)}. */
   public static final java.util.List<String> TOKEN_NAMES = java.util.Collections.unmodifiableList(java.util.Arrays.asList(tokenImage));
 ]]>            </replacevalue>
-            <fileset file="${token-constants-file}" />
+            <file name="${token-constants-file}" />
         </replace>
 
         <replaceregexp>
             <regexp pattern="%%%TOKEN_MGR_NAME%%%" />
             <substitution expression="${tokenmgr-name}" />
-            <fileset file="${token-constants-file}" />
+            <file name="${token-constants-file}" />
         </replaceregexp>
 
         <replaceregexp flags="g">
             <regexp pattern="%%%API_PACK%%%" />
             <substitution expression="${ast-api-package}" />
-            <fileset file="${token-constants-file}" />
+            <file name="${token-constants-file}" />
         </replaceregexp>
 
     </target>
@@ -471,7 +474,7 @@ public final class ${token-constants-name} \{${line.separator}
         <replaceregexp flags="g">
             <regexp pattern="return new ${tokenmgr-name}\(cs\);" />
             <substitution expression="return new ${parser-name}(cs).token_source;" />
-            <fileset file="${token-constants-file}"/>
+            <file name="${token-constants-file}" />
         </replaceregexp>
     </target>