WaE: C6011 Dereferencing NULL pointer warnings

add some asserts for msvc

Change-Id: I3b024b9c1a3160a963ba77ad7313767f2c0a29ce
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/166920
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolan.mcnamara@collabora.com>

unoidl/source/unoidl-check.cxx

@@ -106,6 +106,7 @@ bool getArgument(
         if (delimiter == nullptr) {
             badUsage();
         }
+        assert(delimiter && "badUsage exits otherwise");
         *delimiter = true;
         return false;
     }

unoidl/source/unoidl-write.cxx

@@ -62,6 +62,7 @@ OUString getArgumentUri(sal_uInt32 argument, bool * entities) {
         if (entities == nullptr) {
             badUsage();
         }
+        assert(entities && "badUsage exits otherwise");
         *entities = true;
     } else if (entities != nullptr) {
         *entities = false;