improve for each filter performance

Hack to avoid nfa degraded performance when large methods were present
as it prevented use of the cache.

pitest-entry/src/main/java/org/pitest/mutationtest/build/intercept/javafeatures/ForEachLoopFilter.java

@@ -191,11 +191,6 @@ private Predicate<MutationDetails> mutatesIteratorLoopPlumbing() {
       final int instruction = a.getInstructionIndex();
       final MethodTree method = currentClass.method(a.getId().getLocation()).get();
 
-      //performance hack
-      if (!mightContainForLoop(method.instructions())) {
-        return false;
-      }
-
       final AbstractInsnNode mutatedInstruction = method.instruction(instruction);
 
       Set<AbstractInsnNode> toAvoid = cache.computeIfAbsent(method, this::findLoopInstructions);
@@ -211,11 +206,6 @@ private Set<AbstractInsnNode> findLoopInstructions(MethodTree method) {
             .collect(Collectors.toSet());
   }
 
-  private boolean mightContainForLoop(List<AbstractInsnNode> instructions) {
-    return instructions.stream()
-            .anyMatch(hasNextMethodCall().or(ARRAYLENGTH).asPredicate());
-  }
-
   @Override
   public void end() {
     this.currentClass = null;