[clang] [clang][bytecode][NFC] Remove redundant setSource() call (PR #215716)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `libc-x86_64-debian-dbg-bootstrap-build` running on `libc-x86_64-debian` while building `clang` at step 4 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/200/builds/35194

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

```
Step 4 (annotate) failure: 'python ../llvm-zorg/zorg/buildbot/builders/annotated/libc-linux.py ...' (failure)
...
-- Skipping test for 'libc.src.string.memset_x86_64_opt_avx512' insufficient host cpu features 'AVX512F'
-- Skipping test for 'libc.src.strings.bcmp_x86_64_opt_avx512' insufficient host cpu features 'AVX512BW'
-- Skipping test for 'libc.src.strings.bzero_x86_64_opt_avx512' insufficient host cpu features 'AVX512F'
-- Configuring done
-- Generating done
-- Build files have been written to: /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins
[4/5] cd /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins && /usr/bin/cmake --build /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/ --target check-libc --config Debug
[0/1] Running libc tests via lit
-- Testing: 3818 tests, 32 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80
FAIL: libc :: src/unistd/libc.test.src.unistd.pread_pwrite_test.__build__ (473 of 3818)
******************** TEST 'libc :: src/unistd/libc.test.src.unistd.pread_pwrite_test.__build__' FAILED ********************
[==========] Running 3 tests from 1 test suite.
[ RUN      ] LlvmLibcUniStd.PWriteAndPReadBackTest
/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/llvm-project/libc/test/src/unistd/pread_pwrite_test.cpp:63: FAILURE
      Expected: read_buf
      Which is: hello
To be equal to: OFFSET_TEXT
      Which is: helhello
[  FAILED  ] LlvmLibcUniStd.PWriteAndPReadBackTest
[ RUN      ] LlvmLibcUniStd.PWriteFails
[       OK ] LlvmLibcUniStd.PWriteFails (3 us)
[ RUN      ] LlvmLibcUniStd.PReadFails
[       OK ] LlvmLibcUniStd.PReadFails (2 us)
Ran 3 tests.  PASS: 2  FAIL: 1

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80
FAIL: libc :: src/unistd/libc.test.src.unistd.pread_pwrite_test.__unit__.__build__ (483 of 3818)
******************** TEST 'libc :: src/unistd/libc.test.src.unistd.pread_pwrite_test.__unit__.__build__' FAILED ********************
[==========] Running 3 tests from 1 test suite.
[ RUN      ] LlvmLibcUniStd.PWriteAndPReadBackTest
/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/llvm-project/libc/test/src/unistd/pread_pwrite_test.cpp:47: FAILURE
      Expected: 0
      Which is: 0
To be equal to: static_cast<int>(libc_errno)
      Which is: 2
/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/llvm-project/libc/test/UnitTest/ErrnoCheckingTest.h:54: FAILURE
      Expected: 0
      Which is: 0
To be equal to: static_cast<int>(libc_errno)
      Which is: 2
[  FAILED  ] LlvmLibcUniStd.PWriteAndPReadBackTest
[ RUN      ] LlvmLibcUniStd.PWriteFails
[       OK ] LlvmLibcUniStd.PWriteFails (3 us)
[ RUN      ] LlvmLibcUniStd.PReadFails
[       OK ] LlvmLibcUniStd.PReadFails (2 us)
Ran 3 tests.  PASS: 2  FAIL: 1

Step 7 (check-libc) failure: check-libc (failure)
...
-- Skipping test for 'libc.src.string.memset_x86_64_opt_avx512' insufficient host cpu features 'AVX512F'
-- Skipping test for 'libc.src.strings.bcmp_x86_64_opt_avx512' insufficient host cpu features 'AVX512BW'
-- Skipping test for 'libc.src.strings.bzero_x86_64_opt_avx512' insufficient host cpu features 'AVX512F'
-- Configuring done
-- Generating done
-- Build files have been written to: /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins
[4/5] cd /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins && /usr/bin/cmake --build /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/build/runtimes/runtimes-bins/ --target check-libc --config Debug
[0/1] Running libc tests via lit
-- Testing: 3818 tests, 32 workers --
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80
FAIL: libc :: src/unistd/libc.test.src.unistd.pread_pwrite_test.__build__ (473 of 3818)
******************** TEST 'libc :: src/unistd/libc.test.src.unistd.pread_pwrite_test.__build__' FAILED ********************
[==========] Running 3 tests from 1 test suite.
[ RUN      ] LlvmLibcUniStd.PWriteAndPReadBackTest
/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/llvm-project/libc/test/src/unistd/pread_pwrite_test.cpp:63: FAILURE
      Expected: read_buf
      Which is: hello
To be equal to: OFFSET_TEXT
      Which is: helhello
[  FAILED  ] LlvmLibcUniStd.PWriteAndPReadBackTest
[ RUN      ] LlvmLibcUniStd.PWriteFails
[       OK ] LlvmLibcUniStd.PWriteFails (3 us)
[ RUN      ] LlvmLibcUniStd.PReadFails
[       OK ] LlvmLibcUniStd.PReadFails (2 us)
Ran 3 tests.  PASS: 2  FAIL: 1

********************
Testing:  0.. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80
FAIL: libc :: src/unistd/libc.test.src.unistd.pread_pwrite_test.__unit__.__build__ (483 of 3818)
******************** TEST 'libc :: src/unistd/libc.test.src.unistd.pread_pwrite_test.__unit__.__build__' FAILED ********************
[==========] Running 3 tests from 1 test suite.
[ RUN      ] LlvmLibcUniStd.PWriteAndPReadBackTest
/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/llvm-project/libc/test/src/unistd/pread_pwrite_test.cpp:47: FAILURE
      Expected: 0
      Which is: 0
To be equal to: static_cast<int>(libc_errno)
      Which is: 2
/home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian/libc-x86_64-debian-dbg-bootstrap-build/llvm-project/libc/test/UnitTest/ErrnoCheckingTest.h:54: FAILURE
      Expected: 0
      Which is: 0
To be equal to: static_cast<int>(libc_errno)
      Which is: 2
[  FAILED  ] LlvmLibcUniStd.PWriteAndPReadBackTest
[ RUN      ] LlvmLibcUniStd.PWriteFails
[       OK ] LlvmLibcUniStd.PWriteFails (3 us)
[ RUN      ] LlvmLibcUniStd.PReadFails
[       OK ] LlvmLibcUniStd.PReadFails (2 us)
Ran 3 tests.  PASS: 2  FAIL: 1


```

</details>

https://github.com/llvm/llvm-project/pull/215716