Complete unrolling of loops with small body and trip count one.

Rationale:
Avoids the unnecessary loop control overhead, suspend check,
and exposes more opportunities for constant folding in the
resulting loop body. Fully unrolls loop in execute() of
the Dhrystone benchmark (3% to 8% improvements).

Test: test-art-host

Change-Id: If30f38caea9e9f87a929df041dfb7ed1c227aba3
diff --git a/compiler/optimizing/induction_var_range.h b/compiler/optimizing/induction_var_range.h
index ba14847..6c424b7 100644
--- a/compiler/optimizing/induction_var_range.h
+++ b/compiler/optimizing/induction_var_range.h
@@ -150,9 +150,9 @@
   }
 
   /**
-   * Checks if header logic of a loop terminates.
+   * Checks if header logic of a loop terminates. Sets trip-count tc if known.
    */
-  bool IsFinite(HLoopInformation* loop) const;
+  bool IsFinite(HLoopInformation* loop, /*out*/ int64_t* tc) const;
 
  private:
   /*