Merge pull request #29088 from slavapestov/request-eval-perf-hack

Fix some low-hanging request evaluator performance fruit

lib/Frontend/CompilerInvocation.cpp

@@ -396,6 +396,9 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
   if (Args.getLastArg(OPT_debug_cycles))
     Opts.DebugDumpCycles = true;
 
+  if (Args.getLastArg(OPT_build_request_dependency_graph))
+    Opts.BuildRequestDependencyGraph = true;
+
   if (const Arg *A = Args.getLastArg(OPT_output_request_graphviz)) {
     Opts.RequestEvaluatorGraphVizPath = A->getValue();
   }