Index: clang/lib/CodeGen/CodeGenTypes.h
===================================================================
--- clang/lib/CodeGen/CodeGenTypes.h
+++ clang/lib/CodeGen/CodeGenTypes.h
@@ -80,10 +80,6 @@
 
   llvm::SmallPtrSet<const CGFunctionInfo*, 4> FunctionsBeingProcessed;
 
-  /// True if we didn't layout a function due to a being inside
-  /// a recursive struct conversion, set this to true.
-  bool SkippedLayout;
-
   /// This map keeps cache of llvm::Types and maps clang::Type to
   /// corresponding llvm::Type.
   llvm::DenseMap<const Type *, llvm::Type *> TypeCache;
Index: clang/lib/CodeGen/CodeGenTypes.cpp
===================================================================
--- clang/lib/CodeGen/CodeGenTypes.cpp
+++ clang/lib/CodeGen/CodeGenTypes.cpp
@@ -33,7 +33,6 @@
   : CGM(cgm), Context(cgm.getContext()), TheModule(cgm.getModule()),
     Target(cgm.getTarget()), TheCXXABI(cgm.getCXXABI()),
     TheABIInfo(cgm.getTargetCodeGenInfo().getABIInfo()) {
-  SkippedLayout = false;
 }
 
 CodeGenTypes::~CodeGenTypes() {
@@ -251,8 +250,6 @@
         if (const RecordType *RT = FPT->getParamType(i)->getAs<RecordType>())
           ConvertRecordDeclType(RT->getDecl());
 
-    SkippedLayout = true;
-
     // Return a placeholder type.
     return llvm::StructType::get(getLLVMContext());
   }
@@ -275,7 +272,6 @@
   if (FunctionsBeingProcessed.count(FI)) {
 
     ResultType = llvm::StructType::get(getLLVMContext());
-    SkippedLayout = true;
   } else {
 
     // Otherwise, we're good to go, go ahead and convert it.
@@ -580,10 +576,8 @@
     // int X[] -> [0 x int], unless the element type is not sized.  If it is
     // unsized (e.g. an incomplete struct) just use [0 x i8].
     ResultType = ConvertTypeForMem(A->getElementType());
-    if (!ResultType->isSized()) {
-      SkippedLayout = true;
+    if (!ResultType->isSized())
       ResultType = llvm::Type::getInt8Ty(getLLVMContext());
-    }
     ResultType = llvm::ArrayType::get(ResultType, 0);
     break;
   }
@@ -593,10 +587,8 @@
 
     // Lower arrays of undefined struct type to arrays of i8 just to have a
     // concrete type.
-    if (!EltTy->isSized()) {
-      SkippedLayout = true;
+    if (!EltTy->isSized())
       EltTy = llvm::Type::getInt8Ty(getLLVMContext());
-    }
 
     ResultType = llvm::ArrayType::get(EltTy, A->getSize().getZExtValue());
     break;
@@ -757,12 +749,6 @@
   std::unique_ptr<CGRecordLayout> Layout = ComputeRecordLayout(RD, Ty);
   CGRecordLayouts[Key] = std::move(Layout);
 
-  // If this struct blocked a FunctionType conversion, then recompute whatever
-  // was derived from that.
-  // FIXME: This is hugely overconservative.
-  if (SkippedLayout)
-    TypeCache.clear();
-
   return Ty;
 }