[Bug tree-optimization/68967] Build and test parloops on by default

[vries at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68967

--- Comment #10 from vries at gcc dot gnu.org ---
(In reply to vries from comment #9)
> Though at the end, make check hung in fix-include.

More specifically, the testing of fixincludes hangs:
...
22074 pts/6    S+     0:00  | \_ /bin/sh ./check.sh src/fixincludes/tests/base
23706 pts/6    Sl+    0:00  |     \_ ../../fixincl
23796 pts/6    S+     0:00  |         \_ ../../fixincl
...