Description of problem:

In Fedora 28 it was easy to cross compile on x86_64 to other non-native targets like AArch64 by just using clang. Since Fedora 29 non-native targets are disabled, because of their small use case and the huge memory usage and long build times.

Version-Release number of selected component (if applicable):

clang-7.0.0-0.2.rc1.fc29.x86_64

Steps to Reproduce:

1. echo '// Test' | clang -target armv8a-none-elf -x c -std=c99 -c -o /dev/null -
2. llc -version

Actual results:

On Fedora 29:
The first command displays the error message:
> error: unable to create target: 'No available targets are compatible with this triple.'
The second command shows only native targets:
[...]
  Registered Targets:
    amdgcn  - AMD GCN GPUs
    bpf     - BPF (host endian)
    bpfeb   - BPF (big endian)
    bpfel   - BPF (little endian)
    nvptx   - NVIDIA PTX 32-bit
    nvptx64 - NVIDIA PTX 64-bit
    r600    - AMD GPUs HD2XXX-HD6XXX
    x86     - 32-bit X86: Pentium-Pro and above
    x86-64  - 64-bit X86: EM64T and AMD64

Expected results:

On Fedora 28:
The first command works (no error message).
The second also shows non-native targets like AArch64, ARM and many more:
[...]
  Registered Targets:
    aarch64    - AArch64 (little endian)
    aarch64_be - AArch64 (big endian)
    amdgcn     - AMD GCN GPUs
    arm        - ARM
    arm64      - ARM64 (little endian)
    armeb      - ARM (big endian)
    bpf        - BPF (host endian)
    bpfeb      - BPF (big endian)
    bpfel      - BPF (little endian)
    mips       - Mips
    mips64     - Mips64 [experimental]
    mips64el   - Mips64el [experimental]
    mipsel     - Mipsel
    nvptx      - NVIDIA PTX 32-bit
    nvptx64    - NVIDIA PTX 64-bit
    ppc32      - PowerPC 32
    ppc64      - PowerPC 64
    ppc64le    - PowerPC 64 LE
    r600       - AMD GPUs HD2XXX-HD6XXX
    systemz    - SystemZ
    thumb      - Thumb
    thumbeb    - Thumb (big endian)
    x86        - 32-bit X86: Pentium-Pro and above
    x86-64     - 64-bit X86: EM64T and AMD64