adjust declarations of DenseMapInfo for GCC

Remove the extra qualification and place explicitly in the LLVM
namespace.  This fixes some build issues with GCC 8.2.

Author: compnerd

include/swift/IDE/CodeCompletion.h

@@ -899,26 +899,28 @@ void copyCodeCompletionResults(CodeCompletionResultSink &targetSink,
 } // end namespace ide
 } // end namespace swift
 
-template <> struct llvm::DenseMapInfo<swift::ide::CodeCompletionKeywordKind> {
+namespace llvm {
+template <> struct DenseMapInfo<swift::ide::CodeCompletionKeywordKind> {
   using Kind = swift::ide::CodeCompletionKeywordKind;
   static Kind getEmptyKey() { return Kind(~0u); }
   static Kind getTombstoneKey() { return Kind(~1u); }
   static unsigned getHashValue(const Kind &Val) { return unsigned(Val); }
   static bool isEqual(const Kind &LHS, const Kind &RHS) { return LHS == RHS; }
 };
-template <> struct llvm::DenseMapInfo<swift::ide::CodeCompletionLiteralKind> {
+template <> struct DenseMapInfo<swift::ide::CodeCompletionLiteralKind> {
   using Kind = swift::ide::CodeCompletionLiteralKind;
   static Kind getEmptyKey() { return Kind(~0u); }
   static Kind getTombstoneKey() { return Kind(~1u); }
   static unsigned getHashValue(const Kind &Val) { return unsigned(Val); }
   static bool isEqual(const Kind &LHS, const Kind &RHS) { return LHS == RHS; }
 };
-template <> struct llvm::DenseMapInfo<swift::ide::CodeCompletionDeclKind> {
+template <> struct DenseMapInfo<swift::ide::CodeCompletionDeclKind> {
   using Kind = swift::ide::CodeCompletionDeclKind;
   static Kind getEmptyKey() { return Kind(~0u); }
   static Kind getTombstoneKey() { return Kind(~1u); }
   static unsigned getHashValue(const Kind &Val) { return unsigned(Val); }
   static bool isEqual(const Kind &LHS, const Kind &RHS) { return LHS == RHS; }
 };
+}
 
 #endif // SWIFT_IDE_CODECOMPLETION_H

include/swift/IRGen/Linking.h

@@ -994,7 +994,8 @@ StringRef encodeForceLoadSymbolName(llvm::SmallVectorImpl<char> &buf,
 }
 
 /// Allow LinkEntity to be used as a key for a DenseMap.
-template <> struct llvm::DenseMapInfo<swift::irgen::LinkEntity> {
+namespace llvm {
+template <> struct DenseMapInfo<swift::irgen::LinkEntity> {
   using LinkEntity = swift::irgen::LinkEntity;
   static LinkEntity getEmptyKey() {
     LinkEntity entity;
@@ -1020,4 +1021,5 @@ template <> struct llvm::DenseMapInfo<swift::irgen::LinkEntity> {
            LHS.SecondaryPointer == RHS.SecondaryPointer && LHS.Data == RHS.Data;
   }
 };
+}
 #endif

include/swift/SILOptimizer/Analysis/AccessedStorageAnalysis.h

@@ -94,9 +94,10 @@ class StorageAccessInfo : public AccessedStorage {
 };
 } // namespace swift
 
+namespace llvm {
 // Use the same DenseMapInfo for StorageAccessInfo as for AccessedStorage. None
 // of the subclass bitfields participate in the Key.
-template <> struct llvm::DenseMapInfo<swift::StorageAccessInfo> {
+template <> struct DenseMapInfo<swift::StorageAccessInfo> {
   static swift::StorageAccessInfo getEmptyKey() {
     auto key = DenseMapInfo<swift::AccessedStorage>::getEmptyKey();
     return static_cast<swift::StorageAccessInfo &>(key);
@@ -114,6 +115,7 @@ template <> struct llvm::DenseMapInfo<swift::StorageAccessInfo> {
     return DenseMapInfo<swift::AccessedStorage>::isEqual(LHS, RHS);
   }
 };
+}
 
 namespace swift {
 /// The per-function result of AccessedStorageAnalysis.

include/swift/SILOptimizer/Analysis/AliasAnalysis.h

@@ -306,7 +306,7 @@ bool isLetPointer(SILValue V);
 } // end namespace swift
 
 namespace llvm {
-  template <> struct llvm::DenseMapInfo<AliasKeyTy> {
+  template <> struct DenseMapInfo<AliasKeyTy> {
     static inline AliasKeyTy getEmptyKey() {
       auto Allone = std::numeric_limits<size_t>::max();
       return {0, Allone, nullptr, nullptr};
@@ -331,7 +331,7 @@ namespace llvm {
     }
   };
 
-  template <> struct llvm::DenseMapInfo<MemBehaviorKeyTy> {
+  template <> struct DenseMapInfo<MemBehaviorKeyTy> {
     static inline MemBehaviorKeyTy getEmptyKey() {
       auto Allone = std::numeric_limits<size_t>::max();
       return {0, Allone, RetainObserveKind::RetainObserveKindEnd};

include/swift/Syntax/SyntaxData.h

@@ -294,7 +294,7 @@ class SyntaxData final
 namespace llvm {
   using SD = swift::syntax::SyntaxData;
   using RCSD = swift::RC<SD>;
-  template <> struct llvm::DenseMapInfo<RCSD> {
+  template <> struct DenseMapInfo<RCSD> {
     static inline RCSD getEmptyKey() {
       return SD::make(nullptr, nullptr, 0);
     }

lib/IRGen/LocalTypeDataKind.h

@@ -190,7 +190,8 @@ class LocalTypeDataKey {
 }
 }
 
-template <> struct llvm::DenseMapInfo<swift::irgen::LocalTypeDataKey> {
+namespace llvm {
+template <> struct DenseMapInfo<swift::irgen::LocalTypeDataKey> {
   using LocalTypeDataKey = swift::irgen::LocalTypeDataKey;
   using CanTypeInfo = DenseMapInfo<swift::CanType>;
   static inline LocalTypeDataKey getEmptyKey() {
@@ -209,5 +210,6 @@ template <> struct llvm::DenseMapInfo<swift::irgen::LocalTypeDataKey> {
     return a == b;
   }
 };
+}
 
 #endif