[transferring] Add mangling support for transferring.

This includes runtime support for instantiating transferring param/result in
function types. This is especially important since that is how we instantiate
function types like: typealias Fn = (transferring X) -> ().

rdar://123118061

include/swift/Demangling/Demangle.h

@@ -278,7 +278,7 @@ public:
   /// Prints the whole node tree in readable form to stderr.
   ///
   /// Useful to be called from the debugger.
-  void dump();
+  void dump() LLVM_ATTRIBUTE_USED;
 };
 
 /// Returns the length of the swift mangling prefix of the \p SymbolName.
@@ -555,6 +555,7 @@ struct [[nodiscard]] ManglingError {
     InvalidImplDifferentiability,
     InvalidImplFunctionAttribute,
     InvalidImplParameterConvention,
+    InvalidImplParameterTransferring,
     InvalidMetatypeRepresentation,
     MultiByteRelatedEntity,
     BadValueWitnessKind,