Add trace to SampleClassesAndExecutedMethods

Also log when boot class path profiling is enabled.

Test: manual
Bug: 171432467
Change-Id: I4086638067de79cab3c77c9a0186a43c6cd585f6
diff --git a/runtime/jit/profile_saver.cc b/runtime/jit/profile_saver.cc
index 332c6a7..38f01ff 100644
--- a/runtime/jit/profile_saver.cc
+++ b/runtime/jit/profile_saver.cc
@@ -327,6 +327,8 @@
                                             TypeReferenceCollection* resolved_classes,
                                             MethodReferenceCollection* hot_methods,
                                             MethodReferenceCollection* sampled_methods) {
+  ScopedTrace trace("SampleClassesAndExecutedMethods profile_boot_class_path=" +
+      std::to_string(profile_boot_class_path));
   Thread* const self = Thread::Current();
   ClassLinker* const class_linker = Runtime::Current()->GetClassLinker();
   // Restore profile saver thread priority during the GC critical section. This helps prevent