Revert "In PrepareForBreakPoints, also purge shared function info not referenced by functions."

src/debug.cc

Index: src/debug.cc
diff --git a/src/debug.cc b/src/debug.cc
index 9d31beef0ae80e392bbae40ce83b2043426797cb..6521110a61dc61ebb12271ed7a4bdbd1be2ea08d 100644
--- a/src/debug.cc
+++ b/src/debug.cc
@@ -1894,23 +1894,6 @@ static void RecompileAndRelocateSuspendedGenerators(
 }
 
 
-static bool SkipSharedFunctionInfo(SharedFunctionInfo* shared,
-                                   Object* active_code_marker) {
-  if (!shared->allows_lazy_compilation()) return true;
-  if (!shared->script()->IsScript()) return true;
-  Object* script = shared->script();
-  if (!script->IsScript()) return true;
-  if (Script::cast(script)->type()->value() == Script::TYPE_NATIVE) return true;
-  Code* shared_code = shared->code();
-  return shared_code->gc_metadata() == active_code_marker;
-}
-
-
-static inline bool HasDebugBreakSlots(Code* code) {
-  return code->kind() == Code::FUNCTION && code->has_debug_break_slots();
-}
-
-
 void Debug::PrepareForBreakPoints() {
   // If preparing for the first break point make sure to deoptimize all
   // functions as debugging does not work with optimized code.
@@ -1976,21 +1959,35 @@ void Debug::PrepareForBreakPoints() {
         if (obj->IsJSFunction()) {
           JSFunction* function = JSFunction::cast(obj);
           SharedFunctionInfo* shared = function->shared();
-          if (SkipSharedFunctionInfo(shared, active_code_marker)) continue;
+
+          if (!shared->allows_lazy_compilation()) continue;
+          if (!shared->script()->IsScript()) continue;
+          if (function->IsFromNativeScript()) continue;
+          if (shared->code()->gc_metadata() == active_code_marker) continue;
+
           if (shared->is_generator()) {
             generator_functions.Add(Handle<JSFunction>(function, isolate_));
             continue;
           }
-          if (HasDebugBreakSlots(function->code())) continue;
-          Code* fallback = HasDebugBreakSlots(shared->code()) ? shared->code()
-                                                              : *lazy_compile;
+
           Code::Kind kind = function->code()->kind();
-          if (kind == Code::FUNCTION ||
-              (kind == Code::BUILTIN &&  // Abort in-flight compilation.
-               (function->IsInOptimizationQueue() ||
-                function->IsMarkedForOptimization() ||
-                function->IsMarkedForConcurrentOptimization()))) {
-            function->ReplaceCode(fallback);
+          if (kind == Code::FUNCTION &&
+              !function->code()->has_debug_break_slots()) {
+            function->ReplaceCode(*lazy_compile);
+            function->shared()->ReplaceCode(*lazy_compile);
+          } else if (kind == Code::BUILTIN &&
+              (function->IsInOptimizationQueue() ||
+               function->IsMarkedForOptimization() ||
+               function->IsMarkedForConcurrentOptimization())) {
+            // Abort in-flight compilation.
+            Code* shared_code = function->shared()->code();
+            if (shared_code->kind() == Code::FUNCTION &&
+                shared_code->has_debug_break_slots()) {
+              function->ReplaceCode(shared_code);
+            } else {
+              function->ReplaceCode(*lazy_compile);
+              function->shared()->ReplaceCode(*lazy_compile);
+            }
           }
         } else if (obj->IsJSGeneratorObject()) {
           JSGeneratorObject* gen = JSGeneratorObject::cast(obj);
@@ -2010,12 +2007,6 @@ void Debug::PrepareForBreakPoints() {
           gen->set_continuation(code_offset);
 
           suspended_generators.Add(Handle<JSGeneratorObject>(gen, isolate_));
-        } else if (obj->IsSharedFunctionInfo()) {
-          SharedFunctionInfo* shared = SharedFunctionInfo::cast(obj);
-          if (SkipSharedFunctionInfo(shared, active_code_marker)) continue;
-          if (shared->is_generator()) continue;
-          if (HasDebugBreakSlots(shared->code())) continue;
-          shared->ReplaceCode(*lazy_compile);
         }
       }