[clang-tidy] Don't use a SmallSetVector of an enum.

Summary:
This doesn't work after converting SmallSetVector to use DenseSet.

Instead we can just use a SmallVector.

Reviewers: timshen

Subscribers: nemanjai, cfe-commits

Differential Revision: https://reviews.llvm.org/D25647

llvm-svn: 284873
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/SpecialMemberFunctionsCheck.h b/clang-tools-extra/clang-tidy/cppcoreguidelines/SpecialMemberFunctionsCheck.h
index 227d359..c4e31c2 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/SpecialMemberFunctionsCheck.h
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/SpecialMemberFunctionsCheck.h
@@ -31,7 +31,7 @@
   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
   void onEndOfTranslationUnit() override;
 
-  enum class SpecialMemberFunctionKind {
+  enum class SpecialMemberFunctionKind : uint8_t {
     Destructor,
     CopyConstructor,
     CopyAssignment,
@@ -43,7 +43,7 @@
 
   using ClassDefiningSpecialMembersMap =
       llvm::DenseMap<ClassDefId,
-                     llvm::SmallSetVector<SpecialMemberFunctionKind, 5>>;
+                     llvm::SmallVector<SpecialMemberFunctionKind, 5>>;
 
 private:
   ClassDefiningSpecialMembersMap ClassWithSpecialMembers;