Converting clang's line makers to GHC's line pragma.

Some of clang's line makers have four items:

    ----
    # 1 "<built-in>" 1
    ----

This cannot be parsed by Setup and is left in a template as is,
resulting in compile errors with GHC/clang-wrapper later.
Merge pull request #15 from kazu-yamamoto/new-fix

Converting clang's line makers to GHC's line pragma.