[clang] [compiler-rt] [llvm] ubsan: Add loop detection runtime and e2e tests for -fsanitize-trap-loop. (PR #179011)

[Michał Górny via cfe-commits]

mgorny wrote:

This broke standalone builds:

```
FAILED: [code=1] lib/ubsan/CMakeFiles/RTUbsan_loop_detect.aarch64.dir/ubsan_loop_detect.cpp.o 
/usr/lib/ccache/bin/aarch64-unknown-linux-gnu-clang++-23  -I/var/tmp/portage/llvm-runtimes/compiler-rt-sanitizers-23.0.0.9999/work/compiler-rt/lib/ubsan/..  -O2 -pipe --config=/etc/clang/23/gentoo-rtlib.cfg --config=/etc/clang/23/gentoo-stdlib.cfg --config=/etc/clang/23/gentoo-linker.cfg -Wall -Wno-unused-parameter -std=c++17 -march=armv8-a -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++ -frtti -MD -MT lib/ubsan/CMakeFiles/RTUbsan_loop_detect.aarch64.dir/ubsan_loop_detect.cpp.o -MF lib/ubsan/CMakeFiles/RTUbsan_loop_detect.aarch64.dir/ubsan_loop_detect.cpp.o.d -o lib/ubsan/CMakeFiles/RTUbsan_loop_detect.aarch64.dir/ubsan_loop_detect.cpp.o -c /var/tmp/portage/llvm-runtimes/compiler-rt-sanitizers-23.0.0.9999/work/compiler-rt/lib/ubsan/ubsan_loop_detect.cpp
/var/tmp/portage/llvm-runtimes/compiler-rt-sanitizers-23.0.0.9999/work/compiler-rt/lib/ubsan/ubsan_loop_detect.cpp:13:10: fatal error: 'sanitizer/ubsan_interface.h' file not found
   13 | #include <sanitizer/ubsan_interface.h>
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
```

Looks like it's missing some `-I` path?

https://github.com/llvm/llvm-project/pull/179011