testsuite: mark T4945 as expect_broken

This was working, and then it started failing again; it's a pretty
fragile test anyway because it 'grep's the output of the compiler.

In the mean time, make the CI system quiet down by marking it
appropriately.
Signed-off-by: Austin Seipp <austin@well-typed.com>

testsuite/tests/simplCore/should_compile/all.T

@@ -107,7 +107,7 @@ test('T4918',
      ['$MAKE -s --no-print-directory T4918'])
 
 test('T4945',
-     normal,
+     expect_broken(4945),
      run_command,
      ['$MAKE -s --no-print-directory T4945'])