pcr: aflplusplus: Fix runtime dependencies for LTO
    
    Without ldb we have the following error when running ./configure with
    CC=afl-lto with source code that uses the autools build system:
        clang-13: error: invalid linker name in argument
        '--ld-path=/usr/bin/ld.lld'
    
    And without clang we can't even build a simple hello world:
        $ afl-lto ~/main.c
        afl-cc++4.00c by Michal Zalewski, Laszlo Szekeres, Marc Heuse - mode: LLVM-LTO-PCGUARD
    
        [-] PROGRAM ABORT : Oops, failed to execute '/usr/bin/clang' - check your PATH
                 Location : main(), src/afl-cc.c:2145
    
    Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>