Lower limit for nestedStrongEmphasis because of stack size

Now that there's an extra level of indirection, the stack requirements
are higher. The test was failing on Java 7 but not on 8 because its
default stack size is smaller.

Author: robinst

commonmark/src/test/java/org/commonmark/test/PathologicalTest.java

@@ -32,7 +32,7 @@ protected void finished(long nanos, Description description) {
     @Test
     public void nestedStrongEmphasis() {
         // this is limited by the stack size because visitor is recursive
-        x = 1000;
+        x = 500;
         assertRendering(
                 repeat("*a **a ", x) + "b" + repeat(" a** a*", x),
                 "<p>" + repeat("<em>a <strong>a ", x) + "b" +