Refactor: Makesrna: move generated code further in C++.

This commit moves generated `RNA_blender.h`, `RNA_prototype.h` and
`RNA_blender_cpp.h` headers to become C++ header files.

It also removes the now useless `RNA_EXTERN_C` defines, and just
directly use the `extern` keyword. We do not need anymore `extern "C"`
declarations here.

Pull Request: https://projects.blender.org/blender/blender/pulls/124469

source/blender/python/intern/CMakeLists.txt

@@ -15,7 +15,7 @@ set(INC
   ../../windowmanager
   ../../../../intern/mantaflow/extern
   ../../../../intern/opencolorio
-  # RNA_prototypes.h
+  # RNA_prototypes.hh
   ${CMAKE_BINARY_DIR}/source/blender/makesrna
 )
 
@@ -393,5 +393,5 @@ endif()
 
 blender_add_lib(bf_python "${SRC}" "${INC}" "${INC_SYS}" "${LIB}")
 
-# RNA_prototypes.h
+# RNA_prototypes.hh
 add_dependencies(bf_python bf_rna)

source/blender/python/intern/bpy.cc

@@ -26,7 +26,7 @@
 
 #include "RNA_access.hh"
 #include "RNA_enum_types.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "GPU_state.hh"
 

source/blender/python/intern/bpy_driver.cc

@@ -24,7 +24,7 @@
 #include "BKE_idtype.hh"
 
 #include "RNA_access.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "bpy_rna_driver.h" /* For #pyrna_driver_get_variable_value. */
 

source/blender/python/intern/bpy_operator.cc

@@ -33,7 +33,7 @@
 
 #include "RNA_access.hh"
 #include "RNA_enum_types.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "WM_api.hh"
 #include "WM_types.hh"

source/blender/python/intern/bpy_operator_wrap.cc

@@ -20,7 +20,7 @@
 
 #include "RNA_access.hh"
 #include "RNA_define.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "bpy_intern_string.h"
 #include "bpy_operator_wrap.h" /* own include */

source/blender/python/intern/bpy_props.cc

@@ -30,7 +30,7 @@
 #include "RNA_access.hh"
 #include "RNA_define.hh" /* for defining our own rna */
 #include "RNA_enum_types.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "MEM_guardedalloc.h"
 

source/blender/python/intern/bpy_rna.cc

@@ -44,7 +44,7 @@
 #include "RNA_access.hh"
 #include "RNA_define.hh" /* RNA_def_property_free_identifier */
 #include "RNA_enum_types.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "CLG_log.h"
 

source/blender/python/intern/bpy_rna_anim.cc

@@ -36,7 +36,7 @@
 #include "RNA_access.hh"
 #include "RNA_enum_types.hh"
 #include "RNA_path.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "WM_api.hh"
 #include "WM_types.hh"

source/blender/python/intern/bpy_rna_callback.cc

@@ -18,7 +18,7 @@
 
 #include "RNA_access.hh"
 #include "RNA_enum_types.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "BKE_screen.hh"
 

source/blender/python/intern/bpy_rna_context.cc

@@ -26,7 +26,7 @@
 #include "../generic/python_compat.h"
 
 #include "RNA_access.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "bpy_rna.h"
 

source/blender/python/intern/bpy_rna_data.cc

@@ -26,7 +26,7 @@
 #include "BKE_main.hh"
 
 #include "RNA_access.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "bpy_rna.h"
 #include "bpy_rna_data.h"

source/blender/python/intern/bpy_rna_gizmo.cc

@@ -25,7 +25,7 @@
 #include "../generic/python_compat.h"
 
 #include "RNA_access.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "bpy_rna.h"
 

source/blender/python/intern/bpy_rna_types_capi.cc

@@ -35,7 +35,7 @@
 
 #include "../generic/py_capi_utils.h"
 
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "MEM_guardedalloc.h"
 

source/blender/python/intern/bpy_utils_previews.cc

@@ -17,7 +17,7 @@
 #include "BLI_utildefines.h"
 
 #include "RNA_access.hh"
-#include "RNA_prototypes.h"
+#include "RNA_prototypes.hh"
 
 #include "bpy_rna.h"
 #include "bpy_utils_previews.h"