[llvm] [Support] Prefer AUX vector for page size (PR #126863)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `sanitizer-aarch64-linux` running on `sanitizer-buildbot7` while building `llvm` at step 2 "annotate".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/51/builds/10787

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

```
Step 2 (annotate) failure: 'python ../sanitizer_buildbot/sanitizers/zorg/buildbot/builders/sanitizers/buildbot_selector.py' (failure)
...
+ cut -f 1,2 -d ' '
+ grep -Ev '^#|^$' /home/b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
+ sort -u
+ grep -E '^\+[^+]'
+ diff -u expected.new undefined.new
+getauxval U
+ echo 'Failed: unexpected symbols'
+ exit 1
Failed: unexpected symbols
[3014/3074] Building CXX object compiler-rt/lib/asan/CMakeFiles/RTAsan.aarch64.dir/asan_interceptors.cpp.o
FAILED: compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64.o /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64.o 
cd /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64 && FLAGS=-march=armv8-a CLANG=/home/b/sanitizer-aarch64-linux/build/build_default/./bin/clang /home/b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64.o
ninja: build stopped: subcommand failed.
FAILED: runtimes/runtimes-stamps/runtimes-build /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-stamps/runtimes-build 
cd /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins && /usr/bin/cmake --build .
ninja: build stopped: subcommand failed.

How to reproduce locally: https://github.com/google/sanitizers/wiki/SanitizerBotReproduceBuild

@@@STEP_FAILURE@@@
@@@BUILD_STEP test compiler-rt symbolizer@@@
ninja: Entering directory `build_default'
[0/5] Performing build step for 'builtins'
ninja: no work to do.
[1/5] No install step for 'builtins'
[3/5] Completed 'builtins'
[3/5] Performing configure step for 'runtimes'
Not searching for unused variables given on the command line.
loading initial cache file /home/b/sanitizer-aarch64-linux/build/build_default/projects/runtimes/tmp/runtimes-cache-Release.cmake
-- Performing bootstrapping runtimes build.
CMake Deprecation Warning at /home/b/sanitizer-aarch64-linux/build/llvm-project/cmake/Modules/CMakePolicy.cmake:6 (cmake_policy):
  The OLD behavior for policy CMP0116 will be removed from a future version
  of CMake.

  The cmake-policies(7) manual explains that the OLD behaviors of all
  policies are deprecated and that a policy should be set to OLD only under
  specific short-term circumstances.  Projects should be ported to the NEW
  behavior and not rely on setting a policy to OLD.
Call Stack (most recent call first):
  CMakeLists.txt:18 (include)


-- Building with -fPIC
-- LLVM host triple: aarch64-unknown-linux-gnu
-- LLVM default target triple: aarch64-unknown-linux-gnu
-- Using libunwind testing configuration: /home/b/sanitizer-aarch64-linux/build/llvm-project/libunwind/test/configs/llvm-libunwind-shared.cfg.in
-- Failed to locate sphinx-build executable (missing: SPHINX_EXECUTABLE) 
-- Using libc++abi testing configuration: /home/b/sanitizer-aarch64-linux/build/llvm-project/libcxxabi/test/configs/llvm-libc++abi-shared.cfg.in
-- Using libc++ testing configuration: /home/b/sanitizer-aarch64-linux/build/llvm-project/libcxx/test/configs/llvm-libc++-shared.cfg.in
Step 8 (build compiler-rt symbolizer) failure: build compiler-rt symbolizer (failure)
...
+ cut -f 1,2 -d ' '
+ grep -Ev '^#|^$' /home/b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
+ sort -u
+ grep -E '^\+[^+]'
+ diff -u expected.new undefined.new
+getauxval U
+ echo 'Failed: unexpected symbols'
+ exit 1
Failed: unexpected symbols
[3014/3074] Building CXX object compiler-rt/lib/asan/CMakeFiles/RTAsan.aarch64.dir/asan_interceptors.cpp.o
FAILED: compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64.o /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64.o 
cd /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64 && FLAGS=-march=armv8-a CLANG=/home/b/sanitizer-aarch64-linux/build/build_default/./bin/clang /home/b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64.o
ninja: build stopped: subcommand failed.
FAILED: runtimes/runtimes-stamps/runtimes-build /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-stamps/runtimes-build 
cd /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins && /usr/bin/cmake --build .
ninja: build stopped: subcommand failed.

How to reproduce locally: https://github.com/google/sanitizers/wiki/SanitizerBotReproduceBuild
Step 9 (test compiler-rt symbolizer) failure: test compiler-rt symbolizer (failure)
...
+ sort -u
+ sort -u
+ grep -Ev '^#|^$' /home/b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/lib/sanitizer_common/symbolizer/scripts/global_symbols.txt
+ diff -u expected.new undefined.new
+ grep -E '^\+[^+]'
+getauxval U
+ echo 'Failed: unexpected symbols'
+ exit 1
Failed: unexpected symbols
[54/225] Generating Rtsan-aarch64-Test
FAILED: compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64.o /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64.o 
cd /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64 && FLAGS=-march=armv8-a CLANG=/home/b/sanitizer-aarch64-linux/build/build_default/./bin/clang /home/b/sanitizer-aarch64-linux/build/llvm-project/compiler-rt/lib/sanitizer_common/symbolizer/scripts/build_symbolizer.sh /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/compiler-rt/lib/sanitizer_common/symbolizer/RTSanitizerCommonSymbolizerInternal.aarch64.o
ninja: build stopped: subcommand failed.
FAILED: runtimes/CMakeFiles/check-compiler-rt /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/CMakeFiles/check-compiler-rt 
cd /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins && /usr/bin/cmake --build /home/b/sanitizer-aarch64-linux/build/build_default/runtimes/runtimes-bins/ --target check-compiler-rt --config Release
ninja: build stopped: subcommand failed.

How to reproduce locally: https://github.com/google/sanitizers/wiki/SanitizerBotReproduceBuild

```

</details>

https://github.com/llvm/llvm-project/pull/126863