Restrict GeneratePreagedPrologue to proper functions.

This solves a bug discovered with fast accessors, where a pre-age prologue
was written into a stub. Since StaticMarkingVisitor<.>::IsFlushable will
only flush Code::FUNCTION [1], we'll restrict GeneratePreagedPrologue to
functions, too, instead of adding a Code::STUB restriction.

Also, generalize api accessor test cases to --optimize-for-size.
Also, fix CompilationCacheCachingBehavior for --optimize-for-size.

[1] https://code.google.com/p/chromium/codesearch#chromium/src/v8/src/heap/objects-visiting-inl.h&l=629-632

R=epertoso
BUG=

Review URL: https://codereview.chromium.org/1580323003

Cr-Commit-Position: refs/heads/master@{#33291}

src/compiler.h

@@ -270,10 +270,10 @@ class CompilationInfo {
 
   bool GeneratePreagedPrologue() const {
     // Generate a pre-aged prologue if we are optimizing for size, which
-    // will make code flushing more aggressive. The code for WASM functions
-    // cannot be flushed, so it does not make sense to age them.
+    // will make code flushing more aggressive. Only apply to Code::FUNCTION,
+    // since StaticMarkingVisitor::IsFlushable only flushes proper functions.
     return FLAG_optimize_for_size && FLAG_age_code && !will_serialize() &&
-           !is_debug() && output_code_kind_ != Code::WASM_FUNCTION;
+           !is_debug() && output_code_kind_ == Code::FUNCTION;
   }
 
   void EnsureFeedbackVector();

test/cctest/heap/test-heap.cc

@@ -1567,18 +1567,26 @@ TEST(CompilationCacheCachingBehavior) {
       language_mode);
   CHECK(!info.is_null());
 
+  // Check that the code cache entry survives at least on GC.
+  // (Unless --optimize-for-size, in which case it might get collected
+  // immediately.)
+  if (!FLAG_optimize_for_size) {
     heap->CollectAllGarbage();
-
-  // On second compilation, the hash is replaced by a real cache entry mapping
-  // the source to the shared function info containing the code.
     info = compilation_cache->LookupScript(
         source, Handle<Object>(), 0, 0,
         v8::ScriptOriginOptions(false, true, false), native_context,
         language_mode);
     CHECK(!info.is_null());
+  }
 
+  // Progress code age until it's old and ready for GC.
   while (!info.ToHandleChecked()->code()->IsOld()) {
-    info.ToHandleChecked()->code()->MakeOlder(NO_MARKING_PARITY);
+    // To guarantee progress, we have to MakeOlder with different parities.
+    // We can't just use NO_MARKING_PARITY, since e.g. kExecutedOnceCodeAge is
+    // always NO_MARKING_PARITY and the code age only progresses if the parity
+    // is different.
+    info.ToHandleChecked()->code()->MakeOlder(ODD_MARKING_PARITY);
+    info.ToHandleChecked()->code()->MakeOlder(EVEN_MARKING_PARITY);
   }
 
   heap->CollectAllGarbage();

test/cctest/test-api-accessors.cc

@@ -28,7 +28,7 @@ v8::experimental::FastAccessorBuilder* FastAccessor(v8::Isolate* isolate) {
 
 
 TEST(FastAccessors) {
-  if (i::FLAG_always_opt || i::FLAG_optimize_for_size) return;
+  if (i::FLAG_always_opt) return;
 
   v8::Isolate* isolate = CcTest::isolate();
   v8::HandleScope scope(isolate);

test/cctest/test-api-fast-accessor-builder.cc

@@ -38,7 +38,7 @@ static void NativePropertyAccessor(
 
 // Build a simple "fast accessor" and verify that it is being called.
 TEST(FastAccessor) {
-  if (i::FLAG_always_opt || i::FLAG_optimize_for_size) return;
+  if (i::FLAG_always_opt) return;
 
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
@@ -88,7 +88,7 @@ void AddInternalFieldAccessor(v8::Isolate* isolate,
 
 // "Fast" accessor that accesses an internal field.
 TEST(FastAccessorWithInternalField) {
-  if (i::FLAG_always_opt || i::FLAG_optimize_for_size) return;
+  if (i::FLAG_always_opt) return;
 
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
@@ -120,7 +120,7 @@ TEST(FastAccessorWithInternalField) {
 
 // "Fast" accessor with control flow via ...OrReturnNull methods.
 TEST(FastAccessorOrReturnNull) {
-  if (i::FLAG_always_opt || i::FLAG_optimize_for_size) return;
+  if (i::FLAG_always_opt) return;
 
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
@@ -173,7 +173,7 @@ TEST(FastAccessorOrReturnNull) {
 
 // "Fast" accessor with simple control flow via explicit labels.
 TEST(FastAccessorControlFlowWithLabels) {
-  if (i::FLAG_always_opt || i::FLAG_optimize_for_size) return;
+  if (i::FLAG_always_opt) return;
 
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();
@@ -210,7 +210,7 @@ TEST(FastAccessorControlFlowWithLabels) {
 
 // "Fast" accessor, loading things.
 TEST(FastAccessorLoad) {
-  if (i::FLAG_always_opt || i::FLAG_optimize_for_size) return;
+  if (i::FLAG_always_opt) return;
 
   LocalContext env;
   v8::Isolate* isolate = env->GetIsolate();