[diff] build failure in cc1as_main driver part (r108824)

Hello, cfe-dev!

As before, another API misuse.

Index: tools/clang/tools/driver/cc1as_main.cpp

please ignore that, i just forgot to update the tools/clang tree.
always forget they're separate.

Useful "trick". If you have clang checked out as a sub-tree of llvm (i.e., in <llvm>/tools/clang), you can update both at once by running "make update" in your build directory.