[clang] [compiler-rt] [ubsan] Display correct runtime messages for negative _BitInt (PR #96240)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-sie-ubuntu-fast` running on `sie-linux-worker` while building `clang,compiler-rt` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/144/builds/4702

Here is the relevant piece of the build log for the reference:
```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'Clang :: CodeGen/bit-int-ubsan.c' FAILED ********************
Exit Code: 2

Command Output (stderr):
--
RUN: at line 2: /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/clang -Wno-constant-conversion -Wno-array-bounds -Wno-division-by-zero -Wno-shift-negative-value -Wno-shift-count-negative -Wno-int-to-pointer-cast -fsanitize=array-bounds,enum,float-cast-overflow,integer-divide-by-zero,implicit-unsigned-integer-truncation,implicit-signed-integer-truncation,implicit-integer-sign-change,unsigned-integer-overflow,signed-integer-overflow,shift-base,shift-exponent -O0 -S -emit-llvm -o - /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/CodeGen/bit-int-ubsan.c | /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/CodeGen/bit-int-ubsan.c
+ /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/clang -Wno-constant-conversion -Wno-array-bounds -Wno-division-by-zero -Wno-shift-negative-value -Wno-shift-count-negative -Wno-int-to-pointer-cast -fsanitize=array-bounds,enum,float-cast-overflow,integer-divide-by-zero,implicit-unsigned-integer-truncation,implicit-signed-integer-truncation,implicit-integer-sign-change,unsigned-integer-overflow,signed-integer-overflow,shift-base,shift-exponent -O0 -S -emit-llvm -o - /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/CodeGen/bit-int-ubsan.c
+ /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/CodeGen/bit-int-ubsan.c
/home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/CodeGen/bit-int-ubsan.c:7:10: fatal error: 'stdio.h' file not found
    7 | #include <stdio.h>
      |          ^~~~~~~~~
1 error generated.
FileCheck error: '<stdin>' is empty.
FileCheck command line:  /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/build/bin/FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-sie-ubuntu-fast/llvm-project/clang/test/CodeGen/bit-int-ubsan.c

--

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


```

https://github.com/llvm/llvm-project/pull/96240