Unbreak --gdbjit for embedders.

Embedders don't use d8.cc.  Move gdbjit initialization to api.cc.

BUG=

Review URL: https://codereview.chromium.org/1710253002

Cr-Commit-Position: refs/heads/master@{#34180}

src/api.cc

@@ -35,6 +35,7 @@
 #include "src/debug/debug.h"
 #include "src/deoptimizer.h"
 #include "src/execution.h"
+#include "src/gdb-jit.h"
 #include "src/global-handles.h"
 #include "src/icu_util.h"
 #include "src/isolate-inl.h"
@@ -7160,10 +7161,16 @@ Isolate* Isolate::New(const Isolate::CreateParams& params) {
   if (params.entry_hook) {
     isolate->set_function_entry_hook(params.entry_hook);
   }
-  if (params.code_event_handler) {
+  auto code_event_handler = params.code_event_handler;
+#ifdef ENABLE_GDB_JIT_INTERFACE
+  if (code_event_handler == nullptr && i::FLAG_gdbjit) {
+    code_event_handler = i::GDBJITInterface::EventHandler;
+  }
+#endif  // ENABLE_GDB_JIT_INTERFACE
+  if (code_event_handler) {
     isolate->InitializeLoggingAndCounters();
     isolate->logger()->SetCodeEventHandler(kJitCodeEventDefault,
-                                           params.code_event_handler);
+                                           code_event_handler);
   }
   if (params.counter_lookup_callback) {
     v8_isolate->SetCounterFunction(params.counter_lookup_callback);

src/d8.cc

@@ -26,10 +26,6 @@
 #include "include/v8-testing.h"
 #endif  // V8_SHARED
 
-#if !defined(V8_SHARED) && defined(ENABLE_GDB_JIT_INTERFACE)
-#include "src/gdb-jit.h"
-#endif
-
 #ifdef ENABLE_VTUNE_JIT_INTERFACE
 #include "src/third_party/vtune/v8-vtune.h"
 #endif
@@ -2467,11 +2463,6 @@ int Shell::Main(int argc, char* argv[]) {
     Shell::array_buffer_allocator = &shell_array_buffer_allocator;
   }
   create_params.array_buffer_allocator = Shell::array_buffer_allocator;
-#if !defined(V8_SHARED) && defined(ENABLE_GDB_JIT_INTERFACE)
-  if (i::FLAG_gdbjit) {
-    create_params.code_event_handler = i::GDBJITInterface::EventHandler;
-  }
-#endif
 #ifdef ENABLE_VTUNE_JIT_INTERFACE
   create_params.code_event_handler = vTune::GetVtuneCodeEventHandler();
 #endif