[tests] Cleanup tests that use assertOptimized()/assertUnoptimized().

test/mjsunit/es6/block-let-crankshaft-sloppy.js

Index: test/mjsunit/es6/block-let-crankshaft-sloppy.js
diff --git a/test/mjsunit/es6/block-let-crankshaft-sloppy.js b/test/mjsunit/es6/block-let-crankshaft-sloppy.js
index b5e81f78504435077fce1a36dc9274803a24fdd9..d06153ed8addb03a135c215f0d400a8e8e4dcc46 100644
--- a/test/mjsunit/es6/block-let-crankshaft-sloppy.js
+++ b/test/mjsunit/es6/block-let-crankshaft-sloppy.js
@@ -25,7 +25,7 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --allow-natives-syntax
+// Flags: --allow-natives-syntax --crankshaft
 
 // Check that the following functions are optimizable.
 var functions = [ f1, f2, f3, f4, f5, f6, f7, f8, f9, f10, f11, f12, f13, f14,
@@ -478,5 +478,5 @@ for (var i=0; i<10; i++) {
 f(12);
 g(12);
 
-assertTrue(%GetOptimizationStatus(f) != 2);
-assertTrue(%GetOptimizationStatus(g) != 2);
+assertOptimized(f);
+assertOptimized(g);