[clang] [Static analysis] Encodes a filename before inserting it into a URL. (PR #120123)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-debian-cpp20` running on `clang-debian-cpp20` while building `clang` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/108/builds/7214

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

```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang :: Analysis/scan-build/cxx-name.test' FAILED ********************
Exit Code: 2

Command Output (stdout):
--
# RUN: at line 3
'/usr/bin/perl' '/vol/worker/clang-debian-cpp20/clang-debian-cpp20/llvm-project/clang/tools/scan-build/bin/scan-build' --use-analyzer=/vol/worker/clang-debian-cpp20/clang-debian-cpp20/build/bin/clang-20  sh -c 'echo "CLANG_CXX=/$(basename "$CLANG_CXX")/"' | /vol/worker/clang-debian-cpp20/clang-debian-cpp20/build/bin/FileCheck /vol/worker/clang-debian-cpp20/clang-debian-cpp20/llvm-project/clang/test/Analysis/scan-build/cxx-name.test
# executed command: /usr/bin/perl /vol/worker/clang-debian-cpp20/clang-debian-cpp20/llvm-project/clang/tools/scan-build/bin/scan-build --use-analyzer=/vol/worker/clang-debian-cpp20/clang-debian-cpp20/build/bin/clang-20 sh -c 'echo "CLANG_CXX=/$(basename "$CLANG_CXX")/"'
# .---command stderr------------
# | Can't locate URI/Escape.pm in @INC (you may need to install the URI::Escape module) (@INC contains: /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.36.0 /usr/local/share/perl/5.36.0 /usr/lib/x86_64-linux-gnu/perl5/5.36 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl-base /usr/lib/x86_64-linux-gnu/perl/5.36 /usr/share/perl/5.36 /usr/local/lib/site_perl) at /vol/worker/clang-debian-cpp20/clang-debian-cpp20/llvm-project/clang/tools/scan-build/bin/scan-build line 26.
# | BEGIN failed--compilation aborted at /vol/worker/clang-debian-cpp20/clang-debian-cpp20/llvm-project/clang/tools/scan-build/bin/scan-build line 26.
# `-----------------------------
# error: command failed with exit status: 2
# executed command: /vol/worker/clang-debian-cpp20/clang-debian-cpp20/build/bin/FileCheck /vol/worker/clang-debian-cpp20/clang-debian-cpp20/llvm-project/clang/test/Analysis/scan-build/cxx-name.test
# .---command stderr------------
# | FileCheck error: '<stdin>' is empty.
# | FileCheck command line:  /vol/worker/clang-debian-cpp20/clang-debian-cpp20/build/bin/FileCheck /vol/worker/clang-debian-cpp20/clang-debian-cpp20/llvm-project/clang/test/Analysis/scan-build/cxx-name.test
# `-----------------------------
# error: command failed with exit status: 2

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/120123