compile: set debug compile: Display GCC driver filename
    
    gdb/ChangeLog
    2015-05-24  Jan Kratochvil  <jan.kratochvil@redhat.com>
    
        * compile/compile.c (compile_to_object): Conditionally call set_verbose.
        Conditionally call compile or compile_v0.
    
    include/ChangeLog
    2015-05-24  Jan Kratochvil  <jan.kratochvil@redhat.com>
    
        * gcc-interface.h (enum gcc_base_api_version): Add GCC_FE_VERSION_1.
        (struct gcc_base_vtable): Rename compile to compile_v0.  Update comment
        for compile.  New methods set_verbose and compile.