Make llvm::StringRef to std::string conversions explicit.

This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.

This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.

This doesn't actually modify StringRef yet, I'll do that in a follow-up.

lldb/source/Plugins/LanguageRuntime/RenderScript/RenderScriptRuntime/RenderScriptRuntime.cpp

@@ -1513,7 +1513,7 @@ void RenderScriptRuntime::CaptureScriptInit(RuntimeHook *hook,
       script->type = ScriptDetails::eScriptC;
       script->cache_dir = cache_dir;
       script->res_name = res_name;
-      script->shared_lib = strm.GetString();
+      script->shared_lib = std::string(strm.GetString());
       script->context = addr_t(args[eRsContext]);
     }