Implement LLVM version of jni_compiler to pass 17 jni_compiler tests.

Because we now have both shadow_frame and sirt (which is just for SirtRef<>
in the LLVM version), we define a new function NumStackReferences() as follows:
  NumStackReferences() = NumSirtReferences() + NumShadowFrameReferences().

(cherry picked from commit 18fe89a14d212da9ec6841f4d19d08482a9610b7)

Change-Id: Idd95ee4276801b1555be87934cd9c4f33ab8a88a
diff --git a/src/indirect_reference_table.cc b/src/indirect_reference_table.cc
index f413236..ac5e402 100644
--- a/src/indirect_reference_table.cc
+++ b/src/indirect_reference_table.cc
@@ -241,7 +241,7 @@
 
   JavaVMExt* vm = Runtime::Current()->GetJavaVM();
   if (GetIndirectRefKind(iref) == kSirtOrInvalid &&
-      Thread::Current()->SirtContains(reinterpret_cast<jobject>(iref))) {
+      Thread::Current()->StackReferencesContain(reinterpret_cast<jobject>(iref))) {
     LOG(WARNING) << "Attempt to remove local SIRT entry from IRT, ignoring";
     return true;
   }