[vm] Adds mutator thread asserts around bytecode reading

Change-Id: If5ee92e69f04da8c22983ccdb3d6d9006a2010a5
Reviewed-on: https://dart-review.googlesource.com/c/80562
Commit-Queue: Zach Anderson <zra@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>

runtime/vm/compiler/frontend/bytecode_reader.cc

@@ -57,6 +57,8 @@ void BytecodeMetadataHelper::ReadMetadata(const Function& function) {
     return;
   }
 
+  ASSERT(Thread::Current()->IsMutatorThread());
+
   AlternativeReadingScope alt(&helper_->reader_, &H.metadata_payloads(),
                               md_offset);
 
@@ -766,6 +768,7 @@ RawError* BytecodeReader::ReadFunctionBytecode(Thread* thread,
   ASSERT(!FLAG_precompiled_mode);
   ASSERT(!function.HasBytecode());
   ASSERT(thread->sticky_error() == Error::null());
+  ASSERT(Thread::Current()->IsMutatorThread());
 
   LongJumpScope jump;
   if (setjmp(*jump.Set()) == 0) {

runtime/vm/compiler/jit/compiler.cc

@@ -228,6 +228,7 @@ CompilationPipeline* CompilationPipeline::New(Zone* zone,
 // Compile a function. Should call only if the function has not been compiled.
 //   Arg0: function object.
 DEFINE_RUNTIME_ENTRY(CompileFunction, 1) {
+  ASSERT(thread->IsMutatorThread());
   const Function& function = Function::CheckedHandle(arguments.ArgAt(0));
   Object& result = Object::Handle(zone);
 
@@ -1329,6 +1330,7 @@ RawError* Compiler::CompileAllFunctions(const Class& cls) {
 
 RawError* Compiler::ReadAllBytecode(const Class& cls) {
   Thread* thread = Thread::Current();
+  ASSERT(thread->IsMutatorThread());
   Zone* zone = thread->zone();
   Error& error = Error::Handle(zone, cls.EnsureIsFinalized(thread));
   ASSERT(error.IsNull());
@@ -1370,6 +1372,7 @@ RawObject* Compiler::EvaluateStaticInitializer(const Field& field) {
   LongJumpScope jump;
   if (setjmp(*jump.Set()) == 0) {
     Thread* const thread = Thread::Current();
+    ASSERT(thread->IsMutatorThread());
     NoOOBMessageScope no_msg_scope(thread);
     NoReloadScope no_reload_scope(thread->isolate(), thread);
     // Under lazy compilation initializer has not yet been created, so create

runtime/vm/object.cc

@@ -12505,6 +12505,7 @@ RawError* Library::CompileAll() {
 #if !defined(DART_PRECOMPILED_RUNTIME)
 RawError* Library::ReadAllBytecode() {
   Thread* thread = Thread::Current();
+  ASSERT(thread->IsMutatorThread());
   Zone* zone = thread->zone();
   Error& error = Error::Handle(zone);
   const GrowableObjectArray& libs = GrowableObjectArray::Handle(