[interpreter] Stage bytecode preservation.

This stages the --ignition-preserve-bytecode flag which preserves the
bytecode even when switching to baseline code. It is now implied by the
combined --ignition-staging flag.

R=rmcilroy@chromium.org

Review-Url: https://codereview.chromium.org/2244303003
Cr-Commit-Position: refs/heads/master@{#38648}

src/flag-definitions.h

@@ -299,6 +299,7 @@ DEFINE_BOOL(ignition_staging, false, "use ignition with all staged features")
 DEFINE_IMPLICATION(ignition_staging, ignition)
 DEFINE_IMPLICATION(ignition_staging, ignition_osr)
 DEFINE_IMPLICATION(ignition_staging, turbo_from_bytecode)
+DEFINE_IMPLICATION(ignition_staging, ignition_preserve_bytecode)
 DEFINE_BOOL(ignition_eager, false, "eagerly compile and parse with ignition")
 DEFINE_STRING(ignition_filter, "*", "filter for ignition interpreter")
 DEFINE_BOOL(ignition_deadcode, true,

src/runtime-profiler.cc

@@ -404,7 +404,7 @@ void RuntimeProfiler::MarkCandidatesForOptimization() {
 
     Compiler::CompilationTier next_tier =
         Compiler::NextCompilationTier(function);
-    if (function->shared()->HasBytecodeArray()) {
+    if (function->shared()->code()->is_interpreter_trampoline_builtin()) {
       if (next_tier == Compiler::BASELINE) {
         MaybeBaselineIgnition(function, frame);
       } else {