Remove this test. It requires C++ standard library headers, which we'd

Remove this test. It requires C++ standard library headers, which we'd
like to avoid within the Clang test suite, it doesn't verify the output
at all so it only servers as a test that Clang doesn't crash, and
finally all it does is declare a function that returns a vector and call
it. Probably the biggest thing being tested here is Clang's parsing of
the vector template, and we have lots of good template parsing tests. We
don't need another in codegen.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@138197 91177308-0d34-0410-b5e6-96231b3b80d8