[llvm] [Orc] Fix process-symbols setup in LLJITBuilder for out-of-process case (PR #76244)

[Arthur Eubanks via llvm-commits]

aeubanks wrote:

hi, I believe this is causing some test failures on our mac bots:
```
 FAIL: LLVM :: ExecutionEngine/OrcLazy/debug-descriptor-elf-minimal.ll (46465 of 72625)
 ******************** TEST 'LLVM :: ExecutionEngine/OrcLazy/debug-descriptor-elf-minimal.ll' FAILED ********************
 Exit Code: 2
 
 Command Output (stderr):
 --
 RUN: at line 3: /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/lli --jit-linker=rtdyld      --generate=__dump_jit_debug_descriptor /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm/llvm/test/ExecutionEngine/OrcLazy/debug-descriptor-elf-minimal.ll | /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/FileCheck /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm/llvm/test/ExecutionEngine/OrcLazy/debug-descriptor-elf-minimal.ll
 + /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/lli --jit-linker=rtdyld --generate=__dump_jit_debug_descriptor /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm/llvm/test/ExecutionEngine/OrcLazy/debug-descriptor-elf-minimal.ll
 + /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/FileCheck /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm/llvm/test/ExecutionEngine/OrcLazy/debug-descriptor-elf-minimal.ll
 JIT session error: Symbols not found: [ __jit_debug_descriptor ]
 /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/lli: Failed to materialize symbols: { (main, { main }) }
 FileCheck error: '<stdin>' is empty.
 FileCheck command line:  /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/FileCheck /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm/llvm/test/ExecutionEngine/OrcLazy/debug-descriptor-elf-minimal.ll
 
 --
 
 ********************
 Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60
 FAIL: LLVM :: ExecutionEngine/OrcLazy/debug-objects-elf-minimal.ll (46467 of 72625)
 ******************** TEST 'LLVM :: ExecutionEngine/OrcLazy/debug-objects-elf-minimal.ll' FAILED ********************
 Exit Code: 2
 
 Command Output (stderr):
 --
 RUN: at line 5: /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/lli --jit-linker=rtdyld      --generate=__dump_jit_debug_objects /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm/llvm/test/ExecutionEngine/OrcLazy/debug-objects-elf-minimal.ll | /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/llvm-dwarfdump --diff - | /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/FileCheck /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm/llvm/test/ExecutionEngine/OrcLazy/debug-objects-elf-minimal.ll
 + /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/lli --jit-linker=rtdyld --generate=__dump_jit_debug_objects /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm/llvm/test/ExecutionEngine/OrcLazy/debug-objects-elf-minimal.ll
 + /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/llvm-dwarfdump --diff -
 + /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/FileCheck /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm/llvm/test/ExecutionEngine/OrcLazy/debug-objects-elf-minimal.ll
 JIT session error: Symbols not found: [ __jit_debug_descriptor ]
 /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/lli: Failed to materialize symbols: { (main, { main }) }
 error: -: The file was not recognized as a valid object file
 FileCheck error: '<stdin>' is empty.
 FileCheck command line:  /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm-bootstrap/bin/FileCheck /Volumes/Work/s/w/ir/cache/builder/src/third_party/llvm/llvm/test/ExecutionEngine/OrcLazy/debug-objects-elf-minimal.ll
 
 --
```

can you take a look? happy to provide more details if necessary, although for now this is all I have

https://github.com/llvm/llvm-project/pull/76244