Remove SyntaxASTMap

As far as I can tell, this hasn't ever been really used, it's certainly
not used anymore.

Author: ahoppen

include/swift/AST/SyntaxASTMap.h

@@ -34,8 +34,6 @@
 
 namespace swift {
 
-class SyntaxASTMap;
-
 namespace syntax {
 
 struct SyntaxVisitor;
@@ -58,7 +56,6 @@ const auto NoParent = llvm::None;
 /// their children.
 class Syntax {
   friend struct SyntaxFactory;
-  friend class swift::SyntaxASTMap;
 
 protected:
   /// A strong reference to the root node of the tree in which this piece of

include/swift/Syntax/Syntax.h

@@ -295,30 +295,4 @@ class SyntaxData final
 } // end namespace syntax
 } // end namespace swift
 
-// DenseMapInfo for RC<SyntaxData>, used for a Syntax Node -> lib/AST mapping.
-namespace llvm {
-  using SD = swift::syntax::SyntaxData;
-  using RCSD = swift::RC<SD>;
-  template <> struct DenseMapInfo<RCSD> {
-    static inline RCSD getEmptyKey() {
-      return SD::make(nullptr, nullptr, 0);
-    }
-    static inline RCSD getTombstoneKey() {
-        return SD::make(nullptr, nullptr, 0);
-    }
-    static unsigned getHashValue(const RCSD Value) {
-      unsigned H = 0;
-      H ^= DenseMapInfo<uintptr_t>::getHashValue(reinterpret_cast<const uintptr_t>(Value->getRaw().get()));
-      H ^= DenseMapInfo<uintptr_t>::getHashValue(reinterpret_cast<const uintptr_t>(Value->getParent()));
-      H ^= DenseMapInfo<swift::syntax::CursorIndex>::getHashValue(Value->getIndexInParent());
-      return H;
-    }
-    static bool isEqual(const RCSD LHS, const RCSD RHS) {
-      return LHS->getRaw().get() == RHS->getRaw().get() &&
-             LHS->getParent() == RHS->getParent() &&
-             LHS->getIndexInParent() == RHS->getIndexInParent();
-    }
-  };
-}
-
 #endif // SWIFT_SYNTAX_SYNTAXDATA_H

include/swift/Syntax/SyntaxData.h

@@ -74,7 +74,6 @@ add_swift_host_library(swiftAST STATIC
   ProtocolConformance.cpp
   RawComment.cpp
   RequirementEnvironment.cpp
-  SyntaxASTMap.cpp
   SILLayout.cpp
   Stmt.cpp
   SubstitutionMap.cpp