Fix infinite loop handling non-type template parameters

Fixes infinite loop due to () brackets in a non-type template
parameter containing an expression

Fixes #2418

Non-trivial expressions are still not qualified properly though.

Examples/test-suite/java/cpp14_enable_if_t_runme.java

@@ -0,0 +1,19 @@
+import cpp14_enable_if_t.*;
+
+public class cpp14_enable_if_t_runme {
+
+  static {
+    try {
+        System.loadLibrary("cpp14_enable_if_t");
+    } catch (UnsatisfiedLinkError e) {
+      System.err.println("Native code library failed to load. See the chapter on Dynamic Linking Problems in the SWIG Java documentation for help.\n" + e);
+      System.exit(1);
+    }
+  }
+
+  public static void main(String argv[])
+  {
+    if (cpp14_enable_if_t.enableif5(10, 20) != 30)
+      throw new RuntimeException("enableif5 not working");
+  }
+}