The _misc flags are set via OR operations which aren't safe to do concurrently. We should make setting these flags safe. Besides linked-to bug, there aren't any known bugs with them right now.

Atomically set all of them? Most are set during classfile parsing or loading.

    _misc_rewritten -> set during linking with exclusive access
    _misc_has_nonstatic_fields -> classfile parsing
    _misc_should_verify_class -> classfile parsing
    _misc_unused -> not used
    _misc_is_contended -> classfile parsing
    _misc_has_nonstatic_concrete_methods -> classfile parsing
    _misc_declares_nonstatic_concrete_methods -> classfile parsing
    _misc_has_been_redefined -> set in a redefinition safepoint
    _misc_shared_loading_failed -> set during class loading (exclusive access to InstanceKlass?)
    _misc_is_scratch_class -> set during the redefinition safepoint
    _misc_is_shared_boot_class -> assign_class_loader_type() calls at a safepoint for CDS
    _misc_is_shared_platform_class "
    _misc_is_shared_app_class "
    _misc_has_resolved_methods -> This is unsafe and called during linkResolver
    _misc_has_contended_annotations -> classfile parsing

Maybe has_resolved_methods should be moved to AccessFlags for atomic setting.