compile: Add 'set compile-gcc'

compile: Add 'set compile-gcc'

gdb/ChangeLog
2015-05-24  Jan Kratochvil  <jan.kratochvil@redhat.com>

    * NEWS (Changes since GDB 7.9): Add set compile-gcc and show
    compile-gcc.
    * compile/compile.c (compile_gcc, show_compile_gcc): New.
    (compile_to_object): Implement compile_gcc.
    (_initialize_compile): Install "set compile-gcc".  Initialize
    compile_gcc.

gdb/doc/ChangeLog
2015-05-24  Jan Kratochvil  <jan.kratochvil@redhat.com>

    * gdb.texinfo (Compiling and Injecting Code): Add to subsection
    "Compiler search for the compile command" descriptions of set
    compile-gcc and show compile-gcc.

include/ChangeLog
2015-05-24  Jan Kratochvil  <jan.kratochvil@redhat.com>

    * gcc-interface.h (enum gcc_base_api_version): Update comment for
    GCC_FE_VERSION_1.
    (struct gcc_base_vtable): Rename set_arguments to set_arguments_v0.
    Add set_arguments, set_triplet_regexp and set_driver_filename.