Address HPackedSwitch issues raised after merge

There were some stylistic comments about the merged files.  Fix those.

Add a test that PackedSwitch can be removed by DCE.

Change-Id: Idf45833956e9b58051f942a52b06a1e416606e2e
Signed-off-by: Mark Mendell <mark.p.mendell@intel.com>
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 6b0ccf8..26df241 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -2409,7 +2409,9 @@
 // will be the block containing the next Dex opcode.
 class HPackedSwitch : public HTemplateInstruction<1> {
  public:
-  HPackedSwitch(int32_t start_value, uint32_t num_entries, HInstruction* input,
+  HPackedSwitch(int32_t start_value,
+                uint32_t num_entries,
+                HInstruction* input,
                 uint32_t dex_pc = kNoDexPc)
     : HTemplateInstruction(SideEffects::None(), dex_pc),
       start_value_(start_value),
@@ -2430,8 +2432,8 @@
   DECLARE_INSTRUCTION(PackedSwitch);
 
  private:
-  int32_t start_value_;
-  uint32_t num_entries_;
+  const int32_t start_value_;
+  const uint32_t num_entries_;
 
   DISALLOW_COPY_AND_ASSIGN(HPackedSwitch);
 };