Revert "Revert "Revert "Add implicit null and stack checks for x86"""

Broke the build.

This reverts commit 7fb36ded9cd5b1d254b63b3091f35c1e6471b90e.

Change-Id: I9df0e7446ff0913a0e1276a558b2ccf6c8f4c949
diff --git a/runtime/parsed_options.h b/runtime/parsed_options.h
index fe719b1..d0f3c12 100644
--- a/runtime/parsed_options.h
+++ b/runtime/parsed_options.h
@@ -84,6 +84,11 @@
   bool verify_;
   InstructionSet image_isa_;
 
+  static constexpr uint32_t kExplicitNullCheck = 1;
+  static constexpr uint32_t kExplicitSuspendCheck = 2;
+  static constexpr uint32_t kExplicitStackOverflowCheck = 4;
+  uint32_t explicit_checks_;
+
  private:
   ParsedOptions() {}