Jvm compile counter should increment for double check cache hits

bugfix: This makes the count more accurately represents the total progress of the compile.

Testing Done:
Moved the cache out from under pants and back in before the second check.

    10:35:06 00:00         [zinc-execute]
    10:35:07 00:01           [cache]
                           No cached artifacts for 3 targets.
                           Invalidated 3 targets in 3 target partitions.> /Users/dan/4sq/pants/src/python/pants/backend/jvm/tasks/jvm_compile/jvm_compile.py(622)check_cache()
    -> cached_vts, uncached_vts = self.check_artifact_cache([vts])
    (Pdb) c
    .
                           Hit cache during double check for examples/src/java/org/pantsbuild/example/hello/greet:greet> /Users/dan/4sq/pants/src/python/pants/backend/jvm/tasks/jvm_compile/jvm_compile.py(622)check_cache()
    -> cached_vts, uncached_vts = self.check_artifact_cache([vts])
    (Pdb) c
    .
                           Hit cache during double check for examples/src/scala/org/pantsbuild/example/hello/welcome:welcome> /Users/dan/4sq/pants/src/python/pants/backend/jvm/tasks/jvm_compile/jvm_compile.py(622)check_cache()
    -> cached_vts, uncached_vts = self.check_artifact_cache([vts])
    (Pdb) c

                           [3/3] Compiling 1 zinc source in 1 target (examples/tests/scala/org/pantsbuild/example/hello/welcome:welcome).

Bugs closed: 2635

Reviewed at https://rbcommons.com/s/twitter/r/3188/

src/python/pants/backend/jvm/tasks/jvm_compile/jvm_compile.py

@@ -598,6 +598,19 @@ def exec_graph_key_for_target(self, compile_target):
 
   def _create_compile_jobs(self, classpath_products, compile_contexts, extra_compile_time_classpath,
                            invalid_targets, invalid_vts_partitioned):
+    class Counter(object):
+      def __init__(self, size, initial=0):
+        self.size = size
+        self.count = initial
+
+      def __call__(self):
+        self.count += 1
+        return self.count
+
+      def format_length(self):
+        return len(str(self.size))
+    counter = Counter(len(invalid_vts_partitioned))
+
     def check_cache(vts):
       """Manually checks the artifact cache (usually immediately before compilation.)
 
@@ -614,6 +627,7 @@ def check_cache(vts):
           'Cache returned unexpected target: {} vs {}'.format(cached_vts, [vts])
       )
       self.context.log.info('Hit cache during double check for {}'.format(vts.target.address.spec))
+      counter()
       return True
 
     def should_compile_incrementally(vts):
@@ -627,19 +641,6 @@ def should_compile_incrementally(vts):
         return True
       return os.path.exists(compile_context.analysis_file)
 
-    class Counter(object):
-      def __init__(self, size, initial=0):
-        self.size = size
-        self.count = initial
-
-      def __call__(self):
-        self.count += 1
-        return self.count
-
-      def format_length(self):
-        return len(str(self.size))
-
-    counter = Counter(len(invalid_vts_partitioned))
     def work_for_vts(vts, compile_context):
       progress_message = compile_context.target.address.spec