Replace a static assert by a runtime one, fixes the build of unit tests on ARM

Also safely assert in the non-implemented path that should never be taken in practice,
and would return wrong results.

Eigen/src/Core/util/StaticAssert.h

@@ -93,8 +93,7 @@
         THE_STORAGE_ORDER_OF_BOTH_SIDES_MUST_MATCH,
         OBJECT_ALLOCATED_ON_STACK_IS_TOO_BIG,
         IMPLICIT_CONVERSION_TO_SCALAR_IS_FOR_INNER_PRODUCT_ONLY,
-        STORAGE_LAYOUT_DOES_NOT_MATCH,
-        ROTATION_BY_ILLEGAL_OFFSET
+        STORAGE_LAYOUT_DOES_NOT_MATCH
       };
     };