Executing NoiseTexture.new()._thread_done(BoxShape) crashes Godot

[qarmin]

Godot version:
Godot 3.2.4 rc 2

Issue description:
Executing

	var aa = BoxShape.new()
	NoiseTexture.new()._thread_done(aa)

crashes with backtrace

ERROR: wait_to_finish_func_posix: Condition "!tp" is true.
   At: drivers/unix/thread_posix.cpp:108.
handle_crash: Program crashed with signal 11
Dumping the backtrace. Please include this when reporting the bug on https://github.com/godotengine/godot/issues
[1] /lib/x86_64-linux-gnu/libc.so.6(+0x46210) [0x7f8e84471210] (??:0)
[2] void memdelete<Thread>(Thread*) (/mnt/Miecz/godot3.2/./core/os/memory.h:117)
[3] NoiseTexture::_thread_done(Ref<Image> const&) (/mnt/Miecz/godot3.2/modules/opensimplex/noise_texture.cpp:115)
[4] MethodBind1<Ref<Image> const&>::call(Object*, Variant const**, int, Variant::CallError&) (/mnt/Miecz/godot3.2/./core/method_bind.gen.inc:775 (discriminator 12))
[5] Object::call(StringName const&, Variant const**, int, Variant::CallError&) (/mnt/Miecz/godot3.2/core/object.cpp:919 (discriminator 1))
[6] Variant::call_ptr(StringName const&, Variant const**, int, Variant*, Variant::CallError&) (/mnt/Miecz/godot3.2/core/variant_call.cpp:1129 (discriminator 1))
[7] GDScriptFunction::call(GDScriptInstance*, Variant const**, int, Variant::CallError&, GDScriptFunction::CallState*) (/mnt/Miecz/godot3.2/modules/gdscript/gdscript_function.cpp:1089)
[8] GDScriptInstance::_ml_call_reversed(GDScript*, StringName const&, Variant const**, int) (/mnt/Miecz/godot3.2/modules/gdscript/gdscript.cpp:1269)
[9] GDScriptInstance::call_multilevel_reversed(StringName const&, Variant const**, int) (/mnt/Miecz/godot3.2/modules/gdscript/gdscript.cpp:1278)
[10] Node::_notification(int) (/mnt/Miecz/godot3.2/scene/main/node.cpp:152)
[11] Node::_notificationv(int, bool) (/mnt/Miecz/godot3.2/./scene/main/node.h:46 (discriminator 14))
[12] CanvasItem::_notificationv(int, bool) (/mnt/Miecz/godot3.2/./scene/2d/canvas_item.h:166 (discriminator 3))
[13] Node2D::_notificationv(int, bool) (/mnt/Miecz/godot3.2/./scene/2d/node_2d.h:38 (discriminator 3))
[14] Object::notification(int, bool) (/mnt/Miecz/godot3.2/core/object.cpp:931)
[15] Node::_propagate_ready() (/mnt/Miecz/godot3.2/scene/main/node.cpp:197)
[16] Node::_propagate_ready() (/mnt/Miecz/godot3.2/scene/main/node.cpp:186 (discriminator 2))
[17] Node::_set_tree(SceneTree*) (/mnt/Miecz/godot3.2/scene/main/node.cpp:2560)
[18] SceneTree::init() (/mnt/Miecz/godot3.2/scene/main/scene_tree.cpp:464)
[19] OS_X11::run() (/mnt/Miecz/godot3.2/platform/x11/os_x11.cpp:3628)
[20] /usr/bin/godot(main+0x125) [0x16d2e6b] (/mnt/Miecz/godot3.2/platform/x11/godot_x11.cpp:57)
[21] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf3) [0x7f8e844520b3] (??:0)
[22] /usr/bin/godot(_start+0x2e) [0x16d2c8e] (??:?)

[timothyqiu]

This is no longer valid since the modernization of Thread.