Change iftable to never be null

Simplifies code generation by removing a null check. The null case
is rare.

Ritzperf code size: 13107624 -> 13095336

Also addressed comments from previous CL.

Bug: 32577579

Test: test-art-host, run ritzperf both with CC

Change-Id: I2b31e800867112869d7f0643e16c08826296979e
diff --git a/runtime/arch/arm/entrypoints_init_arm.cc b/runtime/arch/arm/entrypoints_init_arm.cc
index 2a12f1d..de72d3a 100644
--- a/runtime/arch/arm/entrypoints_init_arm.cc
+++ b/runtime/arch/arm/entrypoints_init_arm.cc
@@ -86,7 +86,7 @@
   DefaultInitEntryPoints(jpoints, qpoints);
 
   // Cast
-  qpoints->pInstanceofNonTrivial = artInstanceOfFromCode;;
+  qpoints->pInstanceofNonTrivial = artInstanceOfFromCode;
   qpoints->pCheckInstanceOf = art_quick_check_instance_of;
 
   // Math