Add a testcase for variable-length arrays.

VLAs are special-cased in the frontend. This testcase ensures that the
contract between clang and llvm won't be accidentally broken by future
refactorings.

llvm-svn: 299668
GitOrigin-RevId: 7e8f2ae6498f47253fb4c03d40f50e0d53511056
1 file changed