[cmake] Apply the CMAKE_GUARD parameter of dune_add_Test to dune-istl

Except for those parts that do still rely on the enable trick to test a certain feature set.

I don't understand why you're getting rid of SKIP_ON_77 as well.

Because it is now always applied, check dune-common@9c6942e3

That makes a lot of sense. Thanks.

Added 1 commit:

• 41343018 - [cmake][bugfix] Fix typos in CMakeLists.txt

Looks good. Do you intent to squash to two commits together, as it is still only a branch?

mentioned in commit 897682a6

Status changed to merged

Mentioned in commit 897682a6