Optimize suspend checks in optimizing compiler.

- Remove the ones added during graph build (they were added
  for the baseline code generator).
- Emit them at loop back edges after phi moves, so that the test
  can directly jump to the loop header.
- Fix x86 and x86_64 suspend check by using cmpw instead of cmpl.

Change-Id: I6fad5795a55705d86c9e1cb85bf5d63dadfafa2a
diff --git a/compiler/Android.mk b/compiler/Android.mk
index 7ac1c6b..13c5671 100644
--- a/compiler/Android.mk
+++ b/compiler/Android.mk
@@ -95,6 +95,7 @@
 	optimizing/graph_checker.cc \
 	optimizing/graph_visualizer.cc \
 	optimizing/gvn.cc \
+	optimizing/instruction_simplifier.cc \
 	optimizing/locations.cc \
 	optimizing/nodes.cc \
 	optimizing/optimizing_compiler.cc \