[Compiler] Put background compilation of eager inner functions behind a flag.

src/compiler.cc

Index: src/compiler.cc
diff --git a/src/compiler.cc b/src/compiler.cc
index 41c091fd9821d4b2080a1e4c6350582563a6ff21..5c609fc034760547e09c930f43c6616c27aac290 100644
--- a/src/compiler.cc
+++ b/src/compiler.cc
@@ -386,7 +386,8 @@ bool UseCompilerDispatcher(CompilerDispatcher* dispatcher,
                            DeclarationScope* scope,
                            Handle<SharedFunctionInfo> shared_info,
                            bool is_debug, bool will_serialize) {
-  return dispatcher->IsEnabled() && !is_debug && !will_serialize &&
+  return FLAG_compiler_dispatcher_eager_inner && dispatcher->IsEnabled() &&
+         !is_debug && !will_serialize &&
          !UseAsmWasm(scope, shared_info, is_debug);
 }