[llvm] [runtimes] Fix not correctly searching target builtins directories (PR #103311)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-s390x-linux-lnt` running on `systemz-1` while building `llvm` at step 7 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/136/builds/620

Here is the relevant piece of the build log for the reference:
```
Step 7 (ninja check 1) failure: stage 1 checked (failure)
******************** TEST 'libFuzzer-s390x-default-Linux :: fuzzer-timeout.test' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 1: /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/./bin/clang    -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer  /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/TimeoutTest.cpp -o /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest
+ /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/./bin/clang -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/TimeoutTest.cpp -o /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest
RUN: at line 2: /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/./bin/clang    -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta   --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer  /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/TimeoutEmptyTest.cpp -o /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutEmptyTest
+ /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/./bin/clang -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta --driver-mode=g++ -O2 -gline-tables-only -fsanitize=address,fuzzer -I/home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/TimeoutEmptyTest.cpp -o /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutEmptyTest
RUN: at line 3: not  /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest -timeout=1 2>&1 | FileCheck /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/fuzzer-timeout.test --check-prefix=TimeoutTest
+ not /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest -timeout=1
+ FileCheck /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/fuzzer-timeout.test --check-prefix=TimeoutTest
RUN: at line 12: not  /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest -timeout=1 /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/hi.txt 2>&1 | FileCheck /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/fuzzer-timeout.test --check-prefix=SingleInputTimeoutTest
+ not /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest -timeout=1 /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/hi.txt
+ FileCheck /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/fuzzer-timeout.test --check-prefix=SingleInputTimeoutTest
RUN: at line 16: /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest -timeout=1 -timeout_exitcode=0
+ /home/uweigand/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest -timeout=1 -timeout_exitcode=0
INFO: Running with entropic power schedule (0xFF, 100).
INFO: Seed: 544004015
INFO: Loaded 1 modules   (13 inline 8-bit counters): 13 [0x2aa3eae8e48, 0x2aa3eae8e55), 
INFO: Loaded 1 PC tables (13 PCs): 13 [0x2aa3eae8e58,0x2aa3eae8f28), 
INFO: -max_len is not provided; libFuzzer will not generate inputs larger than 4096 bytes
INFO: A corpus is not provided, starting from an empty corpus
#2	INITED cov: 2 ft: 2 corp: 1/1b exec/s: 0 rss: 32Mb
#164	NEW    cov: 3 ft: 3 corp: 2/2b lim: 4 exec/s: 0 rss: 32Mb L: 1/1 MS: 2 ChangeBit-ChangeBit-
#185	NEW    cov: 4 ft: 4 corp: 3/4b lim: 4 exec/s: 0 rss: 32Mb L: 2/2 MS: 1 CrossOver-
#14041	NEW    cov: 5 ft: 5 corp: 4/6b lim: 135 exec/s: 0 rss: 33Mb L: 2/2 MS: 1 ChangeByte-
#14208	NEW    cov: 6 ft: 6 corp: 5/9b lim: 135 exec/s: 0 rss: 33Mb L: 3/3 MS: 2 ShuffleBytes-CopyPart-
ALARM: working on the last Unit for 1 seconds
       and the timeout value is 1 (use -timeout=N to change)
MS: 2 EraseBytes-InsertByte-; base unit: c74064c97231114b678d2204fde8965f65080db6
0x48,0x69,0x21,
Hi!
artifact_prefix='./'; Test unit written to ./timeout-c0a0ad26a634840c67a210fefdda76577b03a111
Base64: SGkh
==1234910== ERROR: libFuzzer: timeout after 1 seconds
AddressSanitizer:DEADLYSIGNAL
=================================================================
AddressSanitizer:DEADLYSIGNAL
=================================================================
AddressSanitizer: CHECK failed: asan_report.cpp:199 "((current_error_.kind)) == ((kErrorKindInvalid))" (0x1, 0x0) (tid=1234910)
    <empty stack>

MS: 2 EraseBytes-InsertByte-; base unit: c74064c97231114b678d2204fde8965f65080db6
0x48,0x69,0x21,
Hi!
artifact_prefix='./'; Test unit written to ./crash-c0a0ad26a634840c67a210fefdda76577b03a111
Base64: SGkh

--
...

```

https://github.com/llvm/llvm-project/pull/103311