force strict ISO C++ (-Wpedantic)

for Drawing, Image, Inspection, Mesh, MeshPart, Part, Path, Points, Raytracing, ReverseEngineering, Spreadsheet, Start, Surface, Web

TODO: fix several -Woverflow in area

src/Mod/MeshPart/App/Mesher.cpp

@@ -39,6 +39,9 @@
 #if defined(__clang__)
 # pragma clang diagnostic push
 # pragma clang diagnostic ignored "-Woverloaded-virtual"
+#elif defined (__GNUC__)
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wpedantic"
 #endif
 
 #include <SMESH_Gen.hxx>
@@ -70,6 +73,8 @@
 #endif // HAVE_NETGEN
 #if defined(__clang__)
 # pragma clang diagnostic pop
+#elif defined (__GNUC__)
+# pragma GCC diagnostic pop
 #endif
 #endif // HAVE_SMESH