Moved -fblocks from an individual test to check_clang_tidy.py

This way, all tests will benefit from it and will not have to worry
about setting up language options properly.

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@373066 91177308-0d34-0410-b5e6-96231b3b80d8