benchmarks: add 16 and 32 bytes to common sizes

Per Wilco Dijkstra at ARM, 16 and 32 byte copies are much more common
than 8 or 64.

Change-Id: I3699d8bcd5f9dd8a8ccd8564a6cf58d2bd7089f5
Suggested-By: Wilco Dijkstra <wilco.dijkstra@arm.com>
diff --git a/benchmarks/bionic_benchmarks.cpp b/benchmarks/bionic_benchmarks.cpp
index 7139cfa..187ee76 100644
--- a/benchmarks/bionic_benchmarks.cpp
+++ b/benchmarks/bionic_benchmarks.cpp
@@ -39,6 +39,8 @@
 
 static const std::vector<int> kCommonSizes{
   8,
+  16,
+  32,
   64,
   512,
   1 * KB,