[Support] Qualify auto (NFC)

Identified with readability-qualified-auto.

llvm/include/llvm/Support/Allocator.h

@@ -277,7 +277,7 @@ public:
     size_t TotalMemory = 0;
     for (auto I = Slabs.begin(), E = Slabs.end(); I != E; ++I)
       TotalMemory += computeSlabSize(std::distance(Slabs.begin(), I));
-    for (auto &PtrAndSize : CustomSizedSlabs)
+    for (const auto &PtrAndSize : CustomSizedSlabs)
       TotalMemory += PtrAndSize.second;
     return TotalMemory;
   }

llvm/include/llvm/Support/Error.h

@@ -313,7 +313,7 @@ private:
   }
 
   friend raw_ostream &operator<<(raw_ostream &OS, const Error &E) {
-    if (auto P = E.getPtr())
+    if (auto *P = E.getPtr())
       P->log(OS);
     else
       OS << "success";
@@ -373,7 +373,7 @@ class ErrorList final : public ErrorInfo<ErrorList> {
 public:
   void log(raw_ostream &OS) const override {
     OS << "Multiple errors:\n";
-    for (auto &ErrPayload : Payloads) {
+    for (const auto &ErrPayload : Payloads) {
       ErrPayload->log(OS);
       OS << "\n";
     }

llvm/include/llvm/Support/FormatVariadic.h

@@ -94,7 +94,7 @@ public:
         continue;
       }
 
-      auto W = Adapters[R.Index];
+      auto *W = Adapters[R.Index];
 
       FmtAlign Align(*W, R.Where, R.Align, R.Pad);
       Align.format(S, R.Options);

llvm/include/llvm/Support/YAMLTraits.h

@@ -1641,7 +1641,7 @@ void IO::processKeyWithDefault(const char *Key, Optional<T> &Val,
     // usually None.
     bool IsNone = false;
     if (!outputting())
-      if (auto *Node = dyn_cast<ScalarNode>(((Input *)this)->getCurrentNode()))
+      if (const auto *Node = dyn_cast<ScalarNode>(((Input *)this)->getCurrentNode()))
         // We use rtrim to ignore possible white spaces that might exist when a
         // comment is present on the same line.
         IsNone = Node->getRawValue().rtrim(' ') == "<none>";

llvm/lib/Support/SpecialCaseList.cpp

@@ -64,7 +64,7 @@ unsigned SpecialCaseList::Matcher::match(StringRef Query) const {
     return It->second;
   if (Trigrams.isDefinitelyOut(Query))
     return false;
-  for (auto& RegExKV : RegExes)
+  for (const auto &RegExKV : RegExes)
     if (RegExKV.first->match(Query))
       return RegExKV.second;
   return 0;
@@ -209,7 +209,7 @@ bool SpecialCaseList::inSection(StringRef Section, StringRef Prefix,
 unsigned SpecialCaseList::inSectionBlame(StringRef Section, StringRef Prefix,
                                          StringRef Query,
                                          StringRef Category) const {
-  for (auto &SectionIter : Sections)
+  for (const auto &SectionIter : Sections)
     if (SectionIter.SectionMatcher->match(Section)) {
       unsigned Blame =
           inSectionBlame(SectionIter.Entries, Prefix, Query, Category);

llvm/lib/Support/TimeProfiler.cpp

@@ -273,7 +273,7 @@ void llvm::timeTraceProfilerInitialize(unsigned TimeTraceGranularity,
 void llvm::timeTraceProfilerCleanup() {
   delete TimeTraceProfilerInstance;
   std::lock_guard<std::mutex> Lock(Mu);
-  for (auto TTP : *ThreadTimeTraceProfilerInstances)
+  for (auto *TTP : *ThreadTimeTraceProfilerInstances)
     delete TTP;
   ThreadTimeTraceProfilerInstances->clear();
 }

llvm/lib/Support/VirtualFileSystem.cpp

@@ -442,7 +442,7 @@ std::error_code OverlayFileSystem::isLocal(const Twine &Path, bool &Result) {
 std::error_code
 OverlayFileSystem::getRealPath(const Twine &Path,
                                SmallVectorImpl<char> &Output) const {
-  for (auto &FS : FSList)
+  for (const auto &FS : FSList)
     if (FS->exists(Path))
       return FS->getRealPath(Path, Output);
   return errc::no_such_file_or_directory;