[llvm-cov] Hide instantiation views for unexecuted functions

Copying in the full text of the function doesn't help at all when we
already know that it's never executed. Just say that it's unexecuted --
the relevant source text has already been printed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281589 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed