Fix for [ 694111 ] Syntax error crashes Checkstyle.

src/checkstyle/com/puppycrawl/tools/checkstyle/java.g

@@ -940,7 +940,7 @@ options {
 	exportVocab=GeneratedJava; // call the vocabulary "Java"
 	testLiterals=false;        // don't automatically test for literals
 	k=4;                       // four characters of lookahead
-	charVocabulary='\u0003'..'\uFFFF';
+	charVocabulary='\u0003'..'\uFFFE';
 	// without inlining some bitset tests, couldn't do unicode;
 	// I need to make ANTLR generate smaller bitsets; see
 	// bottom of JavaLexer.java

src/checkstyle/com/puppycrawl/tools/checkstyle/java14.g

@@ -59,7 +59,7 @@ options {
 	exportVocab=GeneratedJava14;    // call the vocabulary "Java14",
 	testLiterals=false;    // don't automatically test for literals
 	k=4;                   // four characters of lookahead
-	charVocabulary='\u0003'..'\uFFFF';
+	charVocabulary='\u0003'..'\uFFFE';
 	codeGenBitsetTestThreshold=20;
 }