[clang] fix generation of .debug_aranges with LTO

Right now in case of LTO the section is not emited:

    $ cat test.c
    void __attribute__((optnone)) bar()
    {
    }
    void __attribute__((optnone)) foo()
    {
            bar();
    }
    int main()
    {
            foo();
    }

    $ clang -flto=thin -gdwarf-aranges -g -O3 test.c
    $ eu-readelf -waranges a.out  | fgrep -c -e foo -e bar
    0

    $ clang -gdwarf-aranges -g -O3 test.c
    $ eu-readelf -waranges a.out  | fgrep -c -e foo -e bar
    2

Fix this by passing explicitly --plugin-opt=-generate-arange-section.

Suggested-by: OCHyams <orlando.hyams@sony.com>

Reviewed By: dblaikie, MaskRay

Differential Revision: https://reviews.llvm.org/D133092