[llvm] [RISCV] Don't forward AVL in VSETVLIInfo if it would clobber other definitions (PR #97264)

[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 `llvm` at step 6 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/1146

Here is the relevant piece of the build log for the reference:
```
Step 6 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'SanitizerCommon-hwasan-x86_64-Linux :: Linux/soft_rss_limit_mb_test.cpp' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 2: /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang  --driver-mode=g++ -gline-tables-only -fsanitize=hwaddress -fuse-ld=lld -fsanitize-hwaddress-experimental-aliasing  -m64 -funwind-tables  -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test -ldl -O2 /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test/sanitizer_common/TestCases/Linux/soft_rss_limit_mb_test.cpp -o /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/hwasan-x86_64-Linux/Linux/Output/soft_rss_limit_mb_test.cpp.tmp
+ /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/./bin/clang --driver-mode=g++ -gline-tables-only -fsanitize=hwaddress -fuse-ld=lld -fsanitize-hwaddress-experimental-aliasing -m64 -funwind-tables -I/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test -ldl -O2 /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test/sanitizer_common/TestCases/Linux/soft_rss_limit_mb_test.cpp -o /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/hwasan-x86_64-Linux/Linux/Output/soft_rss_limit_mb_test.cpp.tmp
RUN: at line 5: env HWASAN_OPTIONS=soft_rss_limit_mb=220:quarantine_size=1:allocator_may_return_null=1      /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/hwasan-x86_64-Linux/Linux/Output/soft_rss_limit_mb_test.cpp.tmp 2>&1 | FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test/sanitizer_common/TestCases/Linux/soft_rss_limit_mb_test.cpp -check-prefix=CHECK_MAY_RETURN_1
+ env HWASAN_OPTIONS=soft_rss_limit_mb=220:quarantine_size=1:allocator_may_return_null=1 /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/build/runtimes/runtimes-bins/compiler-rt/test/sanitizer_common/hwasan-x86_64-Linux/Linux/Output/soft_rss_limit_mb_test.cpp.tmp
+ FileCheck /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test/sanitizer_common/TestCases/Linux/soft_rss_limit_mb_test.cpp -check-prefix=CHECK_MAY_RETURN_1
/home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test/sanitizer_common/TestCases/Linux/soft_rss_limit_mb_test.cpp:68:24: error: CHECK_MAY_RETURN_1: expected string not found in input
// CHECK_MAY_RETURN_1: allocating 512 times
                       ^
<stdin>:52:44: note: scanning from here
Some of the malloc calls returned non-null: 256
                                           ^
<stdin>:53:26: note: possible intended match here
==2943521==HWAddressSanitizer: soft rss limit unexhausted (220Mb vs 6Mb)
                         ^

Input file: <stdin>
Check file: /home/buildbot/buildbot-root/llvm-clang-x86_64-gcc-ubuntu/llvm-project/compiler-rt/test/sanitizer_common/TestCases/Linux/soft_rss_limit_mb_test.cpp

-dump-input=help explains the following input dump.

Input was:
<<<<<<
            1: [0] allocating 32 times 
check:63           ^~~~~~~~~~~~~~~~~~~
            2:  [0] 
            3:  [4] 
            4:  [8] 
            5:  [12] 
            6:  [16] 
            7:  [20] 
            8:  [24] 
            9:  [28] 
           10: Some of the malloc calls returned non-null: 32 
check:64       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
           11: [1] allocating 64 times 
           12:  [0] 
           13:  [8] 
           14:  [16] 
           15:  [24] 
           16:  [32] 
           17:  [40] 
           18:  [48] 
           19:  [56] 
           20: Some of the malloc calls returned non-null: 64 
           21: [2] allocating 128 times 
...

```

https://github.com/llvm/llvm-project/pull/97264