[compiler-rt] Fix filename in wasm build of compiler-rt (PR #161875)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-ppc64le-linux-test-suite` running on `ppc64le-clang-test-suite` while building `compiler-rt` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/95/builds/18582

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

```
Step 6 (test-build-unified-tree-check-all) failure: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
...
PASS: LLVM :: tools/llvm-readobj/ELF/file-header-machine-types.test (102280 of 102289)
PASS: ThreadSanitizer-powerpc64le :: deadlock_detector_stress_test.cpp (102281 of 102289)
PASS: lit :: shtest-shell.py (102282 of 102289)
PASS: lit :: shtest-define.py (102283 of 102289)
PASS: ThreadSanitizer-powerpc64le :: restore_stack.cpp (102284 of 102289)
PASS: SanitizerCommon-msan-powerpc64le-Linux :: Linux/signal_segv_handler.cpp (102285 of 102289)
PASS: SanitizerCommon-ubsan-powerpc64le-Linux :: Linux/signal_segv_handler.cpp (102286 of 102289)
PASS: SanitizerCommon-lsan-powerpc64le-Linux :: Linux/signal_segv_handler.cpp (102287 of 102289)
PASS: SanitizerCommon-tsan-powerpc64le-Linux :: Linux/signal_segv_handler.cpp (102288 of 102289)
PASS: SanitizerCommon-asan-powerpc64le-Linux :: Linux/signal_segv_handler.cpp (102289 of 102289)
command timed out: 1200 seconds without output running [b'ninja', b'check-all'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=4315.084015

```

</details>

https://github.com/llvm/llvm-project/pull/161875