Reduce number of addressing modes in GDScript VM

[vnen]

There's now only 3 addressing modes: stack, constant, and member.

Self, class, and nil are now present respectively in the first 3 stack slots. Global and class constants are moved to local constants when compiling. Named globals is only present on editor to use on tool singletons, so its use now emits a new instruction to copy the global to the stack.

This allow us to further optimize the VM later by embedding the addressing modes in the instructions themselves, which is better done with less permutations.

[qarmin]

https://github.com/qarmin/Qarminer/archive/refs/heads/4.0.zip shows error

Invalid call. Nonexistent function 'find' in base 'bool'

https://github.com/qarmin/RegressionTestProject/archive/refs/heads/4.0.zip shows this errors

SCRIPT ERROR: Trying to call a function on a null value.
          at: _ready (res://Start.gd:17)
SCRIPT ERROR: Invalid type in function 'is_parent_class' in base '_ClassDB'. Cannot convert argument 1 from bool to StringName.
          at: _populate (res://Nodes/Nodes.gd:17)

Both projects works fine in master

[qarmin]

Also with first project I have crash when running project without editor

core/variant/array.cpp:91:13: runtime error: applying non-zero offset to non-null pointer 0xfffffffffffffff8 produced null pointer
core/variant/array.cpp:91:27: runtime error: member call on null pointer of type 'struct Vector'
core/templates/vector.h:82:65: runtime error: member access within null pointer of type 'const struct Vector'
core/templates/vector.h:82:48: runtime error: member access within null pointer of type 'const struct Vector'
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] /mnt/Miecz/mojgodot/bin/godot.linuxbsd.tools.64s() [0x1e3d532] (/mnt/Miecz/mojgodot/platform/linuxbsd/crash_handler_linuxbsd.cpp:54)
[2] /lib/x86_64-linux-gnu/libc.so.6(+0x46210) [0x7fbf1f57c210] (??:0)
[3] CowData<Variant>::is_empty() const (/mnt/Miecz/mojgodot/./core/templates/cowdata.h:142)
[4] Vector<Variant>::is_empty() const (/mnt/Miecz/mojgodot/./core/templates/vector.h:82)
[5] Array::is_empty() const (/mnt/Miecz/mojgodot/core/variant/array.cpp:92)
[6] GDScriptFunction::call(GDScriptInstance*, Variant const**, int, Callable::CallError&, GDScriptFunction::CallState*) (/mnt/Miecz/mojgodot/modules/gdscript/gdscript_vm.cpp:2529)
[7] GDScriptInstance::call(StringName const&, Variant const**, int, Callable::CallError&) (/mnt/Miecz/mojgodot/modules/gdscript/gdscript.cpp:1552)
[8] Object::call(StringName const&, Variant const**, int, Callable::CallError&) (/mnt/Miecz/mojgodot/core/object/object.cpp:765 (discriminator 1))
[9] Variant::call(StringName const&, Variant const**, int, Variant&, Callable::CallError&) (/mnt/Miecz/mojgodot/core/variant/variant_call.cpp:713)
[10] GDScriptFunction::call(GDScriptInstance*, Variant const**, int, Callable::CallError&, GDScriptFunction::CallState*) (/mnt/Miecz/mojgodot/modules/gdscript/gdscript_vm.cpp:1394)
[11] GDScriptInstance::call(StringName const&, Variant const**, int, Callable::CallError&) (/mnt/Miecz/mojgodot/modules/gdscript/gdscript.cpp:1552)
[12] ScriptInstance::call(StringName const&, Variant const&, Variant const&, Variant const&, Variant const&, Variant const&) (/mnt/Miecz/mojgodot/core/object/script_language.cpp:311)
[13] Node::_notification(int) (/mnt/Miecz/mojgodot/scene/main/node.cpp:147)
[14] Node::_notificationv(int, bool) (/mnt/Miecz/mojgodot/./scene/main/node.h:45 (discriminator 14))
[15] Object::notification(int, bool) (/mnt/Miecz/mojgodot/core/object/object.cpp:795)
[16] Node::_propagate_ready() (/mnt/Miecz/mojgodot/scene/main/node.cpp:189)
[17] Node::_propagate_ready() (/mnt/Miecz/mojgodot/scene/main/node.cpp:179 (discriminator 2))
[18] Node::_set_tree(SceneTree*) (/mnt/Miecz/mojgodot/scene/main/node.cpp:2525)
[19] SceneTree::initialize() (/mnt/Miecz/mojgodot/scene/main/scene_tree.cpp:395)
[20] OS_LinuxBSD::run() (/mnt/Miecz/mojgodot/platform/linuxbsd/os_linuxbsd.cpp:256)
[21] /mnt/Miecz/mojgodot/bin/godot.linuxbsd.tools.64s(main+0x3fc) [0x1e3b012] (/mnt/Miecz/mojgodot/platform/linuxbsd/godot_linuxbsd.cpp:60)
[22] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf3) [0x7fbf1f55d0b3] (??:0)
[23] /mnt/Miecz/mojgodot/bin/godot.linuxbsd.tools.64s(_start+0x2e) [0x1e3ab5e] (??:?)

[vnen]

@qarmin Thanks! It seems I had forgot to account for the new stack space in one case. Tested with both projects and I don't get script errors anymore nor crashes (with or without editor).

[akien-mga]

Thanks!