build: fix wrapper module generation in CI

Author: LSUDOKO

cmake/templates/hpx.ixx.in

@@ -23,8 +23,6 @@ export module HPX.@cap_libname@;
 // Make sure the exported symbols are name-mangled using standard C++ rules.
 // This is necessary as otherwise the symbols exported from the shared libraries
 // will be exported from the module using a differently encoded name.
-extern "C++" {
-
 #if defined(HPX_MSVC)
 // disable warning C5244: '#include <filename>' in the purview of module
 // 'HPX.@cap_libname@' appears erroneous.  Consider moving that directive before the
@@ -51,5 +49,3 @@ extern "C++" {
 #if defined(HPX_MSVC)
 #pragma warning(pop)
 #endif
-
-}   // extern "C++"

libs/CMakeLists.txt

@@ -338,6 +338,11 @@ foreach(lib ${HPX_LIBS})
   # src/CMakeLists.txt. When all of hpx_full has been modularized the target
   # creation can move here as well.
   if(HPX_WITH_CXX_MODULES)
+    if(NOT TARGET hpx_modules)
+      add_custom_target(hpx_modules ALL)
+      set_target_properties(hpx_modules PROPERTIES FOLDER "Core")
+    endif()
+
     add_library(hpx_${lib}_module STATIC)
     set_target_properties(
       hpx_${lib}_module PROPERTIES POSITION_INDEPENDENT_CODE ON
@@ -353,6 +358,7 @@ foreach(lib ${HPX_LIBS})
       PRIVATE hpx_private_flags
     )
     set_target_properties(hpx_${lib}_module PROPERTIES FOLDER "Core")
+    add_dependencies(hpx_modules hpx_${lib}_module)
 
     add_hpx_source_group(
       NAME hpx_${lib}_module