Add tests demonstrating CFA's treatment of C arrays, compared with GCC's.
These tests recognize two levels of CFA functionality: Classic and Preview. This commit shows that CFA Master implements Classic. Preview refers to Mike's forthcoming changes.
Only the CFA part runs in the nightly build. Under CFA Classic, a limitation is that only some rejection cases are exercised in the nightly build. A hand-driven testing script can access all the cases and CFA Preview will exercise all the cases in the nightly build.
test dimexpr-match-c: how CFA's treatment of C arrays compares with GCC's
test dimexpr-match-cfa: how CFA's treamtment of <containers/array.hfa>-arrays aligns with the above
