[vm/bytecode] Do not emit inferred type if unreachable

Closes: #38965

Change-Id: Id74ed952f2f632fe8028a765d0cf717e04830954
Cq-Include-Trybots: luci.dart.try:vm-ffi-android-debug-arm-try,vm-ffi-android-debug-arm64-try,app-kernel-linux-debug-x64-try,vm-kernel-linux-debug-ia32-try,vm-dartkb-linux-debug-simarm64-try,vm-kernel-win-debug-x64-try,vm-kernel-win-debug-ia32-try,vm-dartkb-linux-debug-x64-try,vm-kernel-precomp-linux-debug-x64-try,vm-dartkb-linux-release-x64-abi-try,vm-kernel-precomp-android-release-arm64-try,vm-kernel-asan-linux-release-x64-try,vm-kernel-linux-release-simarm-try,vm-kernel-linux-release-simarm64-try,vm-kernel-precomp-android-release-arm_x64-try,vm-kernel-precomp-obfuscate-linux-release-x64-try,vm-kernel-reload-rollback-linux-debug-x64-try,vm-kernel-precomp-mac-release-simarm_x64-try,dart-sdk-linux-try
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/122147
Commit-Queue: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>

Author: alexmarkov

pkg/vm/lib/bytecode/gen_bytecode.dart

@@ -1697,7 +1697,7 @@ class BytecodeGenerator extends RecursiveVisitor<Null> {
 
   void _appendInferredType(TreeNode node, int pc) {
     final InferredType md = inferredTypeMetadata[node];
-    if (md == null) {
+    if (md == null || (pc >= 0 && asm.isUnreachable)) {
       return;
     }
     inferredTypesAttribute ??= <Constant>[];

runtime/tests/vm/dart/regress38965_test.dart

@@ -0,0 +1,11 @@
+// Copyright (c) 2017, 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.
+
+// Regression test for dartbug.com/38965.
+
+int a = -1;
+
+main() {
+  false ? (-0.0 as int) : (++a);
+}