[llvm] [ThinLTO] Fix thinlto-bad-summary-5.ll in read-only environments (PR #209513)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-flang-rhel-clang` running on `ppc64le-flang-rhel-test` while building `llvm` at step 6 "test-build-unified-tree-check-flang".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/157/builds/48322

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-unified-tree-check-flang) failure: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
...
PASS: Flang :: Driver/options-loongarch.f90 (4719 of 4729)
PASS: Flang :: Driver/fveclib.f90 (4720 of 4729)
PASS: Flang :: Driver/linker-flags.f90 (4721 of 4729)
PASS: Flang :: Driver/mrecip.f90 (4722 of 4729)
PASS: Flang :: Driver/use-module-error.f90 (4723 of 4729)
PASS: Flang :: Driver/nostdlib.f90 (4724 of 4729)
PASS: Flang :: Driver/fopenmp.f90 (4725 of 4729)
PASS: Flang :: Driver/mcmodel.f90 (4726 of 4729)
PASS: Flang :: Driver/linker-options.f90 (4727 of 4729)
PASS: Flang :: Driver/omp-driver-offload.f90 (4728 of 4729)
command timed out: 1200 seconds without output running [b'ninja', b'check-flang'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=3210.618110

```

</details>

https://github.com/llvm/llvm-project/pull/209513