[clang] [clang-repl] Simplify the logic around out of process execution. NFC (PR #175322)

[Vassil Vassilev via cfe-commits]

vgvassilev wrote:

Do you know where your or runtime is? Looks like it is not anywhere in:
```
[ RUN      ] OutOfProcessInterpreterTest.FindRuntimeInterface
Failure value returned from cantFail wrapped call
OrcRuntime library not found. Checked:
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/tools/clang/unittests/lib/clang/23/lib/amd64-pc-solaris2.11/libclang_rt.orc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/tools/clang/unittests/lib/clang/23/lib/amd64-pc-solaris2.11/liborc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/tools/clang/unittests/lib/clang/23/lib/amd64-pc-solaris2.11/libclang_rt.orc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/tools/clang/unittests/lib/clang/23/lib/amd64-pc-solaris2.11/liborc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/tools/clang/lib/clang/23/lib/amd64-pc-solaris2.11/libclang_rt.orc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/tools/clang/lib/clang/23/lib/amd64-pc-solaris2.11/liborc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/tools/lib/clang/23/lib/amd64-pc-solaris2.11/libclang_rt.orc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/tools/lib/clang/23/lib/amd64-pc-solaris2.11/liborc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/lib/clang/23/lib/amd64-pc-solaris2.11/libclang_rt.orc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/stage1/lib/clang/23/lib/amd64-pc-solaris2.11/liborc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/lib/clang/23/lib/amd64-pc-solaris2.11/libclang_rt.orc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/lib/clang/23/lib/amd64-pc-solaris2.11/liborc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/lib/clang/23/lib/amd64-pc-solaris2.11/libclang_rt.orc_rt.a
  /opt/llvm-buildbot/home/solaris11-amd64/lib/clang/23/lib/amd64-pc-solaris2.11/liborc_rt.a
  /opt/llvm-buildbot/home/lib/clang/23/lib/amd64-pc-solaris2.11/libclang_rt.orc_rt.a
  /opt/llvm-buildbot/home/lib/clang/23/lib/amd64-pc-solaris2.11/liborc_rt.a
  /opt/llvm-buildbot/lib/clang/23/lib/amd64-pc-solaris2.11/libclang_rt.orc_rt.a
  /opt/llvm-buildbot/lib/clang/23/lib/amd64-pc-solaris2.11/liborc_rt.a
  /opt/lib/clang/23/lib/amd64-pc-solaris2.11/libclang_rt.orc_rt.a
  /opt/lib/clang/23/lib/amd64-pc-solaris2.11/liborc_rt.a
  /lib/clang/23/lib/amd64-pc-solaris2.11/libclang_rt.orc_rt.a
  /lib/clang/23/lib/amd64-pc-solaris2.11/liborc_rt.a
UNREACHABLE executed at /opt/llvm-buildbot/home/solaris11-amd64/clang-solaris11-amd64/llvm/llvm/include/llvm/Support/Error.h:810!
```

https://github.com/llvm/llvm-project/pull/175322