[MGTL] Link with openmp; WIN32 use /openmp::llvm

MeshGeoToolsLib/CMakeLists.txt

@@ -5,8 +5,13 @@ get_source_files(SOURCES)
 ogs_add_library(MeshGeoToolsLib ${SOURCES})
 
 target_link_libraries(
-    MeshGeoToolsLib PUBLIC GeoLib MathLib PRIVATE BaseLib MeshToolsLib
+    MeshGeoToolsLib PUBLIC GeoLib MathLib
+    PRIVATE BaseLib MeshToolsLib
+            $<$<TARGET_EXISTS:OpenMP::OpenMP_CXX>:OpenMP::OpenMP_CXX>
 )
+if(WIN32)
+    target_compile_options(MeshGeoToolsLib PUBLIC /openmp::llvm)
+endif()
 
 target_precompile_headers(MeshGeoToolsLib PRIVATE [["BaseLib/Error.h"]]
     [["BaseLib/ConfigTree.h"]] [["BaseLib/Logging.h"]] [["MeshLib/Mesh.h"]]