[compiler-rt] [sanitizer] Print diagnostic if ptrace syscall fails (PR #151406)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `llvm-clang-x86_64-gcc-ubuntu` running on `sie-linux-worker3` while building `compiler-rt` at step 5 "build-unified-tree".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/22276

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

```
Step 5 (build-unified-tree) failure: build (failure)
...
-- Compiler-RT supported architectures: x86_64
-- Generated Sanitizer SUPPORTED_TOOLS list on "Linux" is "asan;lsan;hwasan;msan;tsan;ubsan"
-- sanitizer_common tests on "Linux" will run against "asan;lsan;hwasan;msan;tsan;ubsan"
-- check-shadowcallstack does nothing.
-- Configuring done
-- Generating done
-- Build files have been written to: /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins
27.005 [3/3/227] Linking CXX executable bin/clang-repl
27.064 [2/2/228] Performing build step for 'runtimes'
0.116 [52/3/1] Building CXX object compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.x86_64.dir/sanitizer_stoptheworld_linux_libcdep.cpp.o
FAILED: compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.x86_64.dir/sanitizer_stoptheworld_linux_libcdep.cpp.o 
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang++ --target=x86_64-unknown-linux-gnu -DHAVE_RPC_XDR_H=1 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/lib/sanitizer_common/.. -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Wall -Wno-unused-parameter -O3 -DNDEBUG -m64 -fPIC -fno-builtin -fno-exceptions -fomit-frame-pointer -funwind-tables -fno-stack-protector -fno-sanitize=safe-stack -fvisibility=hidden -fno-lto -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta -O3 -gline-tables-only -Wno-gnu -Wno-variadic-macros -Wno-c99-extensions -ftrivial-auto-var-init=pattern -nostdinc++ -Wno-format -fno-rtti -Wframe-larger-than=570 -Wglobal-constructors -std=c++17 -MD -MT compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.x86_64.dir/sanitizer_stoptheworld_linux_libcdep.cpp.o -MF compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.x86_64.dir/sanitizer_stoptheworld_linux_libcdep.cpp.o.d -o compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibc.x86_64.dir/sanitizer_stoptheworld_linux_libcdep.cpp.o -c /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp:429:5: error: use of undeclared identifier '_exit'
  429 |     _exit(-1);
      |     ^~~~~
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp:435:5: error: use of undeclared identifier '_exit'
  435 |     _exit(0);
      |     ^~~~~
2 errors generated.
0.118 [52/2/2] Building CXX object compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibcNoHooks.x86_64.dir/sanitizer_stoptheworld_linux_libcdep.cpp.o
FAILED: compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibcNoHooks.x86_64.dir/sanitizer_stoptheworld_linux_libcdep.cpp.o 
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang++ --target=x86_64-unknown-linux-gnu -DHAVE_RPC_XDR_H=1 -D_DEBUG -D_GLIBCXX_ASSERTIONS -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/lib/sanitizer_common/.. -fPIC -fno-semantic-interposition -fvisibility-inlines-hidden -Werror=date-time -Werror=unguarded-availability-new -Wall -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wmisleading-indentation -Wctad-maybe-unsupported -fdiagnostics-color -ffunction-sections -fdata-sections -Wall -Wno-unused-parameter -O3 -DNDEBUG -m64 -fPIC -fno-builtin -fno-exceptions -fomit-frame-pointer -funwind-tables -fno-stack-protector -fno-sanitize=safe-stack -fvisibility=hidden -fno-lto -Wthread-safety -Wthread-safety-reference -Wthread-safety-beta -O3 -gline-tables-only -Wno-gnu -Wno-variadic-macros -Wno-c99-extensions -ftrivial-auto-var-init=pattern -nostdinc++ -Wno-format -fno-rtti -Wframe-larger-than=570 -Wglobal-constructors -DSANITIZER_SUPPORTS_WEAK_HOOKS=0 -std=c++17 -MD -MT compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibcNoHooks.x86_64.dir/sanitizer_stoptheworld_linux_libcdep.cpp.o -MF compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibcNoHooks.x86_64.dir/sanitizer_stoptheworld_linux_libcdep.cpp.o.d -o compiler-rt/lib/sanitizer_common/CMakeFiles/RTSanitizerCommonLibcNoHooks.x86_64.dir/sanitizer_stoptheworld_linux_libcdep.cpp.o -c /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp:429:5: error: use of undeclared identifier '_exit'
  429 |     _exit(-1);
      |     ^~~~~
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_stoptheworld_linux_libcdep.cpp:435:5: error: use of undeclared identifier '_exit'
  435 |     _exit(0);
      |     ^~~~~
2 errors generated.
0.443 [52/1/3] Generating /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/compile_commands.json
ninja: build stopped: subcommand failed.
FAILED: runtimes/runtimes-stamps/runtimes-build /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-stamps/runtimes-build 
cd /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins && /usr/bin/cmake/bin/cmake --build .
29.461 [2/1/230] Linking CXX executable tools/clang/unittests/AllClangUnitTests
ninja: build stopped: subcommand failed.

```

</details>

https://github.com/llvm/llvm-project/pull/151406