Undo "Don't include an object header for instructions in the text section."

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index 6bcaeb6895c083d9e7709d144808fbd9e17faa3a..649594e1d06a09a09cfb2d1f12a00069a880e99a 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -934,6 +934,23 @@ Isolate* Isolate::Init(const char* name_prefix,
 }
 
 
+void Isolate::SetupInstructionsSnapshotPage(
+    const uint8_t* instructions_snapshot_buffer) {
+  InstructionsSnapshot snapshot(instructions_snapshot_buffer);
+#if defined(DEBUG)
+  if (FLAG_trace_isolates) {
+    OS::Print("Precompiled instructions are at [0x%" Px ", 0x%" Px ")\n",
+              reinterpret_cast<uword>(snapshot.instructions_start()),
+              reinterpret_cast<uword>(snapshot.instructions_start()) +
+              snapshot.instructions_size());
+  }
+#endif
+  heap_->SetupExternalPage(snapshot.instructions_start(),
+                           snapshot.instructions_size(),
+                           /* is_executable = */ true);
+}
+
+
 void Isolate::SetupDataSnapshotPage(const uint8_t* data_snapshot_buffer) {
   DataSnapshot snapshot(data_snapshot_buffer);
 #if defined(DEBUG)