couple tweaks and comments

Author: VSadov

src/coreclr/nativeaot/Runtime/windows/CoffNativeCodeManager.cpp

@@ -308,6 +308,7 @@ struct CoffNativeMethodInfo
 // Ensure that CoffNativeMethodInfo fits into the space reserved by MethodInfo
 static_assert(sizeof(CoffNativeMethodInfo) <= sizeof(MethodInfo), "CoffNativeMethodInfo too big");
 
+FORCEINLINE
 int CoffNativeCodeManager::LookupUnwindInfoIdx(uint32_t relativePc)
 {
     uint32_t** indices = m_initializedIndices;

src/coreclr/nativeaot/Runtime/windows/CoffNativeCodeManager.h

@@ -44,6 +44,8 @@ class CoffNativeCodeManager : public ICodeManager
     PTR_PTR_VOID m_pClasslibFunctions;
     uint32_t m_nClasslibFunctions;
 
+    // used to publish a reference to the index once initialized.
+    // if the reference is not null, the index can be accessed through it.
     uint32_t** volatile m_initializedIndices;
     uint32_t m_indexCount;
     uint32_t* m_indices[8];