fixup! use std::string instead of llvm::StringRef

Author: charles-zablit

lldb/source/Plugins/Language/Swift/SwiftLanguage.cpp

@@ -1945,7 +1945,7 @@ GetDemangledBasename(const SymbolContext &sc) {
   auto [demangled_name, info] = *info_or_err;
 
   return demangled_name.substr(info.BasenameRange.first,
-                               info.BasenameRange.second);
+                               info.BasenameRange.second - info.BasenameRange.first);
 }
 
 static llvm::Expected<std::string>
@@ -1961,7 +1961,7 @@ GetDemangledFunctionPrefix(const SymbolContext &sc) {
         "DemangledInfo for '%s does not have suffix range.",
         demangled_name.data());
 
-  return demangled_name.substr(info.PrefixRange.first, info.PrefixRange.second);
+  return demangled_name.substr(info.PrefixRange.first, info.PrefixRange.second - info.PrefixRange.first);
 }
 
 static llvm::Expected<std::string>
@@ -1977,7 +1977,7 @@ GetDemangledFunctionSuffix(const SymbolContext &sc) {
         "DemangledInfo for '%s does not have suffix range.",
         demangled_name.data());
 
-  return demangled_name.substr(info.SuffixRange.first, info.SuffixRange.second);
+  return demangled_name.substr(info.SuffixRange.first, info.SuffixRange.second - info.SuffixRange.first);
 }
 
 static bool PrintDemangledArgumentList(Stream &s, const SymbolContext &sc) {
@@ -1996,7 +1996,7 @@ static bool PrintDemangledArgumentList(Stream &s, const SymbolContext &sc) {
     return false;
 
   s << demangled_name.substr(info.ArgumentsRange.first,
-                             info.ArgumentsRange.second);
+                             info.ArgumentsRange.second - info.ArgumentsRange.first);
 
   return true;
 }