[clang] [clang-repl] Fixing vulnerabilities with respect to orc runtime (PR #165852)

[Anutosh Bhat via cfe-commits]

anutosh491 wrote:

Addressed the suggestions above. 

Trying to forcefully mess up the path in my case shows me this
```
anutosh491 at vv-nuc:/build/anutosh491/llvm-project/build/bin$ ./clang-repl   --oop-executor=$PWD/llvm-jitlink-executor
clang version 22.0.0git (https://github.com/anutosh491/llvm-project.git 81ad8fbc2bb09bae61ed59316468011e4a42cf47)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /build/anutosh491/llvm-project/build/bin
Build config: +unoptimized, +assertions
clang-repl: OrcRuntime library not found in: /build/anutosh491/llvm-project/build/lib/clang/22/lib/linux; /build/anutosh491/llvm-project/build/lib/clang/22/lib/x86_64-unknown-linux-gnu
```
Which is covering both paths as we want.

https://github.com/llvm/llvm-project/pull/165852