[lldb][NFCI] Remove use of ConstString from OptionValueLanguage

[bulbazord]

Summary

ConstString is simply not needed here.

[JDevlieghere]

LGTM

lldb/source/Interpreter/OptionValueLanguage.cpp

Status OptionValueLanguage::SetValueFromString(llvm::StringRef value,
   Status error;
   switch (op) {
   case eVarSetOperationClear:
     Clear();
     break;
 
   case eVarSetOperationReplace:
   case eVarSetOperationAssign: {
-    ConstString lang_name(value.trim());
     LanguageSet languages_for_types = Language::GetLanguagesSupportingTypeSystems();
-    LanguageType new_type =
-        Language::GetLanguageTypeFromString(lang_name.GetStringRef());
+    LanguageType new_type = Language::GetLanguageTypeFromString(value.trim());
     if (new_type && languages_for_types[new_type]) {
       m_value_was_set = true;
       m_current_value = new_type;
     } else {
       StreamString error_strm;
       error_strm.Printf("invalid language type '%s', ", value.str().c_str());
       error_strm.Printf("valid values are:\n");
       for (int bit : languages_for_types.bitvector.set_bits()) {