Remove obsolete JSFunction::IsOptimizable predicate.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index ea67e2cbe672eda297ee79a5c859bdf90d73cddf..9b8483af088f3db157913255d7aeb15a6cf371ee 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -9807,7 +9807,7 @@ void JSFunction::JSFunctionIterateBody(int object_size, ObjectVisitor* v) {
 void JSFunction::MarkForOptimization() {
   Isolate* isolate = GetIsolate();
   DCHECK(!IsOptimized());
-  DCHECK(shared()->allows_lazy_compilation() || IsOptimizable());
+  DCHECK(shared()->allows_lazy_compilation());
   set_code_no_write_barrier(
       isolate->builtins()->builtin(Builtins::kCompileOptimized));
   // No write barrier required, since the builtin is part of the root set.
@@ -9831,7 +9831,7 @@ void JSFunction::AttemptConcurrentOptimization() {
   }
   DCHECK(!IsInOptimizationQueue());
   DCHECK(!IsOptimized());
-  DCHECK(shared()->allows_lazy_compilation() || IsOptimizable());
+  DCHECK(shared()->allows_lazy_compilation());
   DCHECK(isolate->concurrent_recompilation_enabled());
   if (FLAG_trace_concurrent_recompilation) {
     PrintF("  ** Marking ");
@@ -9839,7 +9839,7 @@ void JSFunction::AttemptConcurrentOptimization() {
     PrintF(" for concurrent recompilation.\n");
   }
   set_code_no_write_barrier(
-      GetIsolate()->builtins()->builtin(Builtins::kCompileOptimizedConcurrent));
+      isolate->builtins()->builtin(Builtins::kCompileOptimizedConcurrent));
   // No write barrier required, since the builtin is part of the root set.
 }