[NFC][SetVector] Update some usages of SetVector to SmallSetVector

This patch is a continuation of D152497. It updates usages of SetVector
that were found in llvm/ and clang/ which were originally specifying either
SmallPtrSet or SmallVector to just using SmallSetVector, as the overhead
of SetVector is reduced with D152497.

This also helps clean up the code a fair bit, and gives a decent speed
boost at -O0 (~0.2%):
https://llvm-compile-time-tracker.com/compare.php?from=9ffdabecabcddde298ff313f5353f9e06590af62&to=97f1c0cde42ba85eaa67cbe89bec8fe45b801f21&stat=instructions%3Au

Differential Revision: https://reviews.llvm.org/D152522

clang/include/clang/Sema/Sema.h

@@ -792,8 +792,7 @@ class Sema final {
   /// we won't know until all lvalue-to-rvalue and discarded value conversions
   /// have been applied to all subexpressions of the enclosing full expression.
   /// This is cleared at the end of each full expression.
-  using MaybeODRUseExprSet = llvm::SetVector<Expr *, SmallVector<Expr *, 4>,
-                                             llvm::SmallPtrSet<Expr *, 4>>;
+  using MaybeODRUseExprSet = llvm::SmallSetVector<Expr *, 4>;
   MaybeODRUseExprSet MaybeODRUseExprs;
 
   std::unique_ptr<sema::FunctionScopeInfo> CachedFunctionScope;

clang/lib/Sema/SemaOverload.cpp

@@ -8024,8 +8024,7 @@ namespace {
 /// enumeration types.
 class BuiltinCandidateTypeSet  {
   /// TypeSet - A set of types.
-  typedef llvm::SetVector<QualType, SmallVector<QualType, 8>,
-                          llvm::SmallPtrSet<QualType, 8>> TypeSet;
+  typedef llvm::SmallSetVector<QualType, 8> TypeSet;
 
   /// PointerTypes - The set of pointer types that will be used in the
   /// built-in candidates.

clang/lib/Sema/SemaStmt.cpp

@@ -1729,9 +1729,7 @@ Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body,
 
 namespace {
   // Use SetVector since the diagnostic cares about the ordering of the Decl's.
-  using DeclSetVector =
-      llvm::SetVector<VarDecl *, llvm::SmallVector<VarDecl *, 8>,
-                      llvm::SmallPtrSet<VarDecl *, 8>>;
+  using DeclSetVector = llvm::SmallSetVector<VarDecl *, 8>;
 
   // This visitor will traverse a conditional statement and store all
   // the evaluated decls into a vector.  Simple is set to true if none

llvm/include/llvm/ADT/GenericCycleInfo.h

@@ -28,10 +28,10 @@
 #ifndef LLVM_ADT_GENERICCYCLEINFO_H
 #define LLVM_ADT_GENERICCYCLEINFO_H
 
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/GenericSSAContext.h"
 #include "llvm/ADT/GraphTraits.h"
 #include "llvm/ADT/SetVector.h"
-#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 
@@ -64,7 +64,7 @@ template <typename ContextT> class GenericCycle {
   /// Basic blocks that are contained in the cycle, including entry blocks,
   /// and including blocks that are part of a child cycle.
   using BlockSetVectorT = SetVector<BlockT *, SmallVector<BlockT *, 8>,
-                                    SmallPtrSet<const BlockT *, 8>>;
+                                    DenseSet<const BlockT *>, 8>;
   BlockSetVectorT Blocks;
 
   /// Depth of the cycle in the tree. The root "cycle" is at depth 0.

llvm/include/llvm/CodeGen/LiveRangeEdit.h

@@ -97,8 +97,7 @@ class LiveRangeEdit : private MachineRegisterInfo::Delegate {
   /// a load, eliminate the register by folding the def into the use.
   bool foldAsLoad(LiveInterval *LI, SmallVectorImpl<MachineInstr *> &Dead);
 
-  using ToShrinkSet = SetVector<LiveInterval *, SmallVector<LiveInterval *, 8>,
-                                SmallPtrSet<LiveInterval *, 8>>;
+  using ToShrinkSet = SmallSetVector<LiveInterval *, 8>;
 
   /// Helper for eliminateDeadDefs.
   void eliminateDeadDef(MachineInstr *MI, ToShrinkSet &ToShrink);

llvm/include/llvm/Transforms/Scalar/SROA.h

@@ -105,7 +105,7 @@ class SROAPass : public PassInfoMixin<SROAPass> {
   /// directly promoted. Finally, each time we rewrite a use of an alloca other
   /// the one being actively rewritten, we add it back onto the list if not
   /// already present to ensure it is re-visited.
-  SetVector<AllocaInst *, SmallVector<AllocaInst *, 16>> Worklist;
+  SmallSetVector<AllocaInst *, 16> Worklist;
 
   /// A collection of instructions to delete.
   /// We try to batch deletions to simplify code and make things a bit more
@@ -120,7 +120,7 @@ class SROAPass : public PassInfoMixin<SROAPass> {
   ///
   /// Note that we have to be very careful to clear allocas out of this list in
   /// the event they are deleted.
-  SetVector<AllocaInst *, SmallVector<AllocaInst *, 16>> PostPromotionWorklist;
+  SmallSetVector<AllocaInst *, 16> PostPromotionWorklist;
 
   /// A collection of alloca instructions we can directly promote.
   std::vector<AllocaInst *> PromotableAllocas;
@@ -130,7 +130,7 @@ class SROAPass : public PassInfoMixin<SROAPass> {
   /// All of these PHIs have been checked for the safety of speculation and by
   /// being speculated will allow promoting allocas currently in the promotable
   /// queue.
-  SetVector<PHINode *, SmallVector<PHINode *, 8>> SpeculatablePHIs;
+  SmallSetVector<PHINode *, 8> SpeculatablePHIs;
 
   /// A worklist of select instructions to rewrite prior to promoting
   /// allocas.

llvm/lib/Analysis/InlineCost.cpp

@@ -2680,9 +2680,7 @@ InlineResult CallAnalyzer::analyze() {
   // basic blocks in a breadth-first order as we insert live successors. To
   // accomplish this, prioritizing for small iterations because we exit after
   // crossing our threshold, we use a small-size optimized SetVector.
-  typedef SetVector<BasicBlock *, SmallVector<BasicBlock *, 16>,
-                    SmallPtrSet<BasicBlock *, 16>>
-      BBSetVector;
+  typedef SmallSetVector<BasicBlock *, 16> BBSetVector;
   BBSetVector BBWorklist;
   BBWorklist.insert(&F.getEntryBlock());
 

llvm/lib/CodeGen/AsmPrinter/DwarfDebug.h

@@ -318,9 +318,7 @@ class DwarfDebug : public DebugHandlerBase {
 
   /// This is a collection of subprogram MDNodes that are processed to
   /// create DIEs.
-  SetVector<const DISubprogram *, SmallVector<const DISubprogram *, 16>,
-            SmallPtrSet<const DISubprogram *, 16>>
-      ProcessedSPNodes;
+  SmallSetVector<const DISubprogram *, 16> ProcessedSPNodes;
 
   /// If nonnull, stores the current machine function we're processing.
   const MachineFunction *CurFn = nullptr;