[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!
> > ```
> 
> Hi, this PR also breaks our X86 Linux build in clang unittests when orc runtime library does not exists. It seem to be failing at the `cantFail` here: https://github.com/llvm/llvm-project/blob/main/clang/unittests/Interpreter/OutOfProcessInterpreterTests.cpp#L167 Is this #176198 supposed to fix it?

Yes. 

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