[vm] Re-tighten requirements that the node type be set before writing.

Fixes the case where the Image name and type was not written
to the v8 snapshot profile in non-precompiled mode.

Adds core-jit snapshot tests to the v8 snapshot profile writer test.

In core-jit and app-aot-elf modes, verify that all bytes in the
snapshot sections are accounted for in the profile.

Bug: https://github.com/dart-lang/sdk/issues/45787

TEST=vm/dart{,_2}/v8_snapshot_profile_writer_test

Cq-Include-Trybots: luci.dart.try:vm-kernel-precomp-linux-product-x64-try,vm-kernel-precomp-linux-release-x64-try,vm-kernel-precomp-linux-debug-x64-try
Change-Id: I88be309cdea6293d768e2fa458492387d70fde22
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/196323
Commit-Queue: Tess Strickland <sstrickl@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>

pkg/native_stack_traces/CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 0.4.1
+
+- Exported some ELF utilities in lib/elf.dart for use in Dart tests.
+
 ## 0.4.0
 
 - Stable null safe version of package.

pkg/native_stack_traces/lib/elf.dart

@@ -0,0 +1,11 @@
+// Copyright (c) 2021, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+export 'src/elf.dart' show Elf, Symbol;
+export 'src/constants.dart'
+    show
+        isolateDataSymbolName,
+        isolateSymbolName,
+        vmDataSymbolName,
+        vmSymbolName;

pkg/native_stack_traces/lib/src/constants.dart

@@ -12,5 +12,11 @@ const String buildIdNoteName = "GNU";
 // The dynamic symbol name for the VM instructions section.
 const String vmSymbolName = "_kDartVmSnapshotInstructions";
 
+// The dynamic symbol name for the VM data section.
+const String vmDataSymbolName = "_kDartVmSnapshotData";
+
 // The dynamic symbol name for the isolate instructions section.
 const String isolateSymbolName = "_kDartIsolateSnapshotInstructions";
+
+// The dynamic symbol name for the isolate data section.
+const String isolateDataSymbolName = "_kDartIsolateSnapshotData";

pkg/native_stack_traces/pubspec.yaml

@@ -1,6 +1,6 @@
 name: native_stack_traces
 description: Utilities for working with non-symbolic stack traces.
-version: 0.4.0
+version: 0.4.1
 
 homepage: https://github.com/dart-lang/sdk/tree/master/pkg/native_stack_traces