Add virtual functions getter

[Prazek]

Summary

Small refactor

[rjmccall]

This is a potentially significant pessimization. Can you turn this into a range iterator of some sort?

include/clang/AST/VTableBuilder.h

public:
   ArrayRef<VTableComponent> vtable_components() const {
     return VTableComponents;
   }
 
   ArrayRef<VTableThunkTy> vtable_thunks() const {
     return VTableThunks;
   }
 
+  llvm::SmallVector<const CXXMethodDecl *, 8> virtualFunctions() const {
+    llvm::SmallVector<const CXXMethodDecl *, 8> VFunctions;
+    for (const auto &VtableComponent : vtable_components()) {
+      // Skip everything except functions.
+      if (!VtableComponent.isUsedFunctionPointerKind())
+        continue;
+      VFunctions.push_back(VtableComponent.getFunctionDecl());
+    }
+    return VFunctions;
+  }
+
   AddressPointLocation getAddressPoint(BaseSubobject Base) const {
     assert(AddressPoints.count(Base) && "Did not find address point!");
     return AddressPoints.find(Base)->second;
   }
 
   const AddressPointsMapTy &getAddressPoints() const {
     return AddressPoints;
   }

lib/CodeGen/ItaniumCXXABI.cpp

public:
   classifyRTTIUniqueness(QualType CanTy,
                          llvm::GlobalValue::LinkageTypes Linkage) const;
   friend class ItaniumRTTIBuilder;
 
   void emitCXXStructor(const CXXMethodDecl *MD, StructorType Type) override;
 
  private:
    bool hasAnyVirtualInlineFunction(const CXXRecordDecl *RD) const {
-    const auto &VtableLayout =
+     const auto &VTableLayout =
          CGM.getItaniumVTableContext().getVTableLayout(RD);
-
-    for (const auto &VtableComponent : VtableLayout.vtable_components()) {
-      // Skip empty slot.
-      if (!VtableComponent.isUsedFunctionPointerKind())
-        continue;
-
-      const CXXMethodDecl *Method = VtableComponent.getFunctionDecl();
-      if (Method->getCanonicalDecl()->isInlined())
+     for (const auto *VFunction : VTableLayout.virtualFunctions())
+       if (VFunction->getCanonicalDecl()->isInlined())
          return true;
-    }
      return false;
   }
 
   bool isVTableHidden(const CXXRecordDecl *RD) const {
     const auto &VtableLayout =
             CGM.getItaniumVTableContext().getVTableLayout(RD);
 
     for (const auto &VtableComponent : VtableLayout.vtable_components()) {
       if (VtableComponent.isRTTIKind()) {