* src/build-msvctools/cc-msvc.cc: Allow to preprocess-only. Make sure to run the compiler, and not the linker, when doing only pre-processing. Required to compile libgpg_error, which pre-processes a header file.

#include <google/protobuf/stubs/common.h>

int
main()
{
    GOOGLE_PROTOBUF_VERIFY_VERSION;
    google::protobuf::ShutdownProtobufLibrary();
    return 0;
}