Ensure coherency of call kinds for LocationSummary.

The coherency is enforced with checks added in the `InvokeRuntime`
helper, that we now also use on x86 and x86_64.

Change-Id: I8cb92b042f25dc3c5fd390e9c61a45b477d081f4
diff --git a/compiler/optimizing/code_generator.h b/compiler/optimizing/code_generator.h
index eb63b49..540da1c 100644
--- a/compiler/optimizing/code_generator.h
+++ b/compiler/optimizing/code_generator.h
@@ -98,6 +98,8 @@
     return saved_fpu_stack_offsets_[reg];
   }
 
+  virtual bool IsFatal() const { return false; }
+
   virtual const char* GetDescription() const = 0;
 
  protected: