Discern between virtual and abstract class bindings

* Previous "virtual" classes (which can't be instantiated) are not corretly named "abstract".
* Added a new "virtual" category for classes, they can't be instantiated from the editor, but can be inherited from script and extensions.
* Converted a large amount of classes from "abstract" to "virtual" where it makes sense.

Most classes that make sense have been converted. Missing:

* Physics servers
* VideoStream
* Script* classes.

which will go in a separate PR due to the complexity involved.

Author: reduz

.github/workflows/linux_builds.yml

@@ -36,7 +36,9 @@ jobs:
             tests: true
             sconsflags: float=64 use_asan=yes use_ubsan=yes
             proj-test: true
-            godot-cpp-test: true
+            # Can be turned off for PRs that intentionally break compat with godot-cpp,
+            # until both the upstream PR and the matching godot-cpp changes are merged.
+            godot-cpp-test: false
             bin: "./bin/godot.linuxbsd.double.tools.64.san"
             build-mono: false
             # Skip 2GiB artifact speeding up action.

core/extension/gdnative_interface.h

@@ -194,6 +194,7 @@ typedef void *GDExtensionClassInstancePtr;
 
 typedef GDNativeBool (*GDNativeExtensionClassSet)(GDExtensionClassInstancePtr p_instance, const GDNativeStringNamePtr p_name, const GDNativeVariantPtr p_value);
 typedef GDNativeBool (*GDNativeExtensionClassGet)(GDExtensionClassInstancePtr p_instance, const GDNativeStringNamePtr p_name, GDNativeVariantPtr r_ret);
+typedef uint64_t (*GDNativeExtensionClassGetRID)(GDExtensionClassInstancePtr p_instance);
 
 typedef struct {
 	uint32_t type;
@@ -228,6 +229,7 @@ typedef struct {
 	GDNativeExtensionClassCreateInstance create_instance_func; /* this one is mandatory */
 	GDNativeExtensionClassFreeInstance free_instance_func; /* this one is mandatory */
 	GDNativeExtensionClassGetVirtual get_virtual_func;
+	GDNativeExtensionClassGetRID get_rid_func;
 	void *class_userdata;
 } GDNativeExtensionClassCreationInfo;