Mangler: add a dump() function for debugging

Author: eeckstein

include/swift/Basic/Mangler.h

@@ -111,6 +111,8 @@ class Mangler {
   static void verify(StringRef mangledName);
   static void verifyOld(StringRef mangledName);
 
+  void dump();
+
   /// Appends a mangled identifier string.
   void appendIdentifier(StringRef ident);
 

lib/Basic/Mangler.cpp

@@ -239,6 +239,10 @@ void Mangler::appendIdentifier(StringRef ident) {
   recordOpStat("<identifier>", OldPos);
 }
 
+void Mangler::dump() {
+  llvm::errs() << Buffer.str() << '\n';
+}
+
 bool Mangler::tryMangleSubstitution(const void *ptr) {
   auto ir = Substitutions.find(ptr);
   if (ir == Substitutions.end())