Fix pydoc null pointer dereference with missing arg type

Processing doxygen @param comments for a parameter whose name did not
appear in the function declaration would cause a segfault due to a
null pointer dereference.

Adding test cases for both variadic function (no specified arguments)
and @param comment that references an argument that is not named in
the function prototype.  Both of these cases previously segfaulted.

Examples/test-suite/java/doxygen_basic_translate_runme.java

@@ -94,6 +94,13 @@ public class doxygen_basic_translate_runme {
     		" @param x Horizontal coordinate.\n" +
     		" @return Arc tangent of <code>y/x</code>.\n" +
     		"");
+    wantedComments.put("doxygen_basic_translate.doxygen_basic_translate.function8()",
+		" Test variadic function\n" +
+		"");
+
+    wantedComments.put("doxygen_basic_translate.doxygen_basic_translate.function9(int)",
+		" Test unnamed argument\n" +
+		"");    
 
     // and ask the parser to check comments for us
     System.exit(parser.check(wantedComments));