Avoid flushing the icache unnecessarily when updating target addresses in code.

src/ic.cc

Index: src/ic.cc
diff --git a/src/ic.cc b/src/ic.cc
index a6efdab56b49f041ca9c53cbf49dead9c2f7a65b..4b109cef0282a709d44e7c69abae4e9b0482bb81 100644
--- a/src/ic.cc
+++ b/src/ic.cc
@@ -859,7 +859,11 @@ void LoadIC::UpdateCaches(LookupResult* lookup,
     // This is the first time we execute this inline cache.
     // Set the target to the pre monomorphic stub to delay
     // setting the monomorphic state.
-    set_target(*pre_monomorphic_stub());
+    // No need to flush the icache since the pre_monomorphic_stub will be the
+    // same code as the initialize_stub - it is just used as a marker to
+    // identify when we should move to monomorphic, and will be correctly read
+    // via raw_target() even if the wrong stub was called.
+    set_target(*pre_monomorphic_stub(), SKIP_ICACHE_FLUSH_IF_ATOMIC);
     TRACE_IC("LoadIC", name);
     return;
   }
@@ -1309,7 +1313,11 @@ MaybeHandle<Object> StoreIC::Store(Handle<Object> object,
   if (FLAG_use_ic) {
     if (state() == UNINITIALIZED) {
       Handle<Code> stub = pre_monomorphic_stub();
-      set_target(*stub);
+      // No need to flush the icache since the pre_monomorphic_stub will be the
+      // same code as the initialize_stub - it is just used as a marker to
+      // identify when we should move to monomorphic, and will be correctly read
+      // via raw_target() even if the wrong stub was called.
+      set_target(*stub, SKIP_ICACHE_FLUSH_IF_ATOMIC);
       TRACE_IC("StoreIC", name);
     } else if (can_store) {
       UpdateCaches(&lookup, receiver, name, value);