[llvm] [IR] Fix llvm.powi intrinsic decl (PR #216160)

[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/8599

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

```
Step 7 (ninja check 1) failure: stage 1 checked (failure)
******************** TEST 'libFuzzer-s390x-default-Linux :: fuzzer-timeout.test' FAILED ********************
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
/home/buildbot/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/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer  /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/TimeoutTest.cpp -o /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest
# executed command: /home/buildbot/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/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/TimeoutTest.cpp -o /home/buildbot/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/buildbot/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/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer  /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/TimeoutEmptyTest.cpp -o /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutEmptyTest
# executed command: /home/buildbot/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/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/TimeoutEmptyTest.cpp -o /home/buildbot/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/buildbot/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/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/fuzzer-timeout.test --check-prefix=TimeoutTest
# executed command: not /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest -timeout=1
# executed command: FileCheck /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/fuzzer-timeout.test --check-prefix=TimeoutTest
# RUN: at line 12
not  /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest -timeout=1 /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/hi.txt 2>&1 | FileCheck /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/fuzzer-timeout.test --check-prefix=SingleInputTimeoutTest
# executed command: not /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/stage1/runtimes/runtimes-bins/compiler-rt/test/fuzzer/S390XDefaultLinuxConfig/Output/fuzzer-timeout.test.tmp-TimeoutTest -timeout=1 /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/hi.txt
# executed command: FileCheck /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/test/fuzzer/fuzzer-timeout.test --check-prefix=SingleInputTimeoutTest
# RUN: at line 16
/home/buildbot/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
# executed command: /home/buildbot/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
# .---command stderr------------
# | INFO: Running with entropic power schedule (0xFF, 100).
# | INFO: Seed: 500764865
# | INFO: Loaded 1 modules   (12 inline 8-bit counters): 12 [0x2aa26e4be88, 0x2aa26e4be94), 
# | INFO: Loaded 1 PC tables (12 PCs): 12 [0x2aa26e4be98,0x2aa26e4bf58), 
# | 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: 114Mb
# | #930	NEW    cov: 3 ft: 3 corp: 2/2b lim: 11 exec/s: 0 rss: 114Mb L: 1/1 MS: 3 ShuffleBytes-ChangeBit-ChangeBit-
# | #934	NEW    cov: 4 ft: 4 corp: 3/4b lim: 11 exec/s: 0 rss: 114Mb L: 2/2 MS: 4 CrossOver-CrossOver-CrossOver-CopyPart-
# | #18007	NEW    cov: 5 ft: 5 corp: 4/7b lim: 177 exec/s: 0 rss: 114Mb L: 3/3 MS: 3 ChangeBit-CopyPart-ChangeBit-
# | #18081	NEW    cov: 6 ft: 6 corp: 5/9b lim: 177 exec/s: 0 rss: 114Mb L: 2/3 MS: 4 ChangeByte-CopyPart-ShuffleBytes-CrossOver-
# | ALARM: working on the last Unit for 1 seconds
# |        and the timeout value is 1 (use -timeout=N to change)
# | MS: 1 ChangeByte-; base unit: bf397014ecbce0b1be8d9011c77f6181927a357f
# | 0x48,0x69,0x21,
# | Hi!
# | artifact_prefix='./'; Test unit written to ./timeout-c0a0ad26a634840c67a210fefdda76577b03a111
# | Base64: SGkh
# | ==332805== ERROR: libFuzzer: timeout after 1 seconds
# | /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/stage1/./bin/llvm-symbolizer: error: 'linux-vdso.so.1': No such file or directory
# |     #0 0x02aa26dc47a5 in __sanitizer_print_stack_trace /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/asan/asan_stack.cpp:87:3
# |     #1 0x02aa26cfb3c7 in fuzzer::PrintStackTrace() /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer/FuzzerUtil.cpp:210:5
# |     #2 0x02aa26cd5d5b in fuzzer::Fuzzer::AlarmCallback() /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer/FuzzerLoop.cpp:304:5
# |     #3 0x03ffd7be753f  (linux-vdso.so.1+0x53f) (BuildId: 7f9e7ac3791c85b6b507b3f0271194f1c6227c58)
# |     #4 0x02aa26cf8e31 in Popcountll /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer/FuzzerBuiltins.h:29:54
# |     #5 0x02aa26cf8e31 in HandleCmp<unsigned int> /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer/FuzzerTracePC.cpp:381:30
# |     #6 0x02aa26cf8e31 in __sanitizer_cov_trace_const_cmp4 /home/buildbot/sandbox/buildbot/clang-s390x-linux-lnt/llvm/compiler-rt/lib/fuzzer/FuzzerTracePC.cpp:505:15
...

```

</details>

https://github.com/llvm/llvm-project/pull/216160