[llvm] [VPlan] Add ComputeFindLastIVResult opcode (NFC). (PR #132689)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `lldb-aarch64-ubuntu` running on `linaro-lldb-aarch64-ubuntu` while building `llvm` at step 6 "test".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/59/builds/14950

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

```
Step 6 (test) failure: build (failure)
...
PASS: lldb-api :: lang/c/complex_int/TestComplexInt.py (714 of 2110)
PASS: lldb-api :: lang/c/cpp_keyword_identifiers/TestCppKeywordsAsCIdentifiers.py (715 of 2110)
PASS: lldb-api :: lang/c/const_variables/TestConstVariables.py (716 of 2110)
PASS: lldb-api :: lang/c/find_struct_type/TestFindStructTypes.py (717 of 2110)
PASS: lldb-api :: lang/c/conflicting-symbol/TestConflictingSymbol.py (718 of 2110)
PASS: lldb-api :: lang/c/flexible-array-members/TestCFlexibleArrayMembers.py (719 of 2110)
UNSUPPORTED: lldb-api :: lang/c/full_lto_stepping/TestFullLtoStepping.py (720 of 2110)
PASS: lldb-api :: lang/c/enum_types/TestEnumTypes.py (721 of 2110)
XFAIL: lldb-api :: lang/c/local_types/TestUseClosestType.py (722 of 2110)
PASS: lldb-api :: lang/c/forward/TestForwardDeclaration.py (723 of 2110)
FAIL: lldb-api :: lang/c/fpeval/TestFPEval.py (724 of 2110)
******************** TEST 'lldb-api :: lang/c/fpeval/TestFPEval.py' FAILED ********************
Script:
--
/usr/bin/python3.10 /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/test/API/dotest.py -u CXXFLAGS -u CFLAGS --env LLVM_LIBS_DIR=/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./lib --env LLVM_INCLUDE_DIR=/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/include --env LLVM_TOOLS_DIR=/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./bin --arch aarch64 --build-dir /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lldb-test-build.noindex --lldb-module-cache-dir /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lldb-test-build.noindex/module-cache-lldb/lldb-api --clang-module-cache-dir /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/lldb-test-build.noindex/module-cache-clang/lldb-api --executable /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./bin/lldb --compiler /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./bin/clang --dsymutil /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./bin/dsymutil --make /usr/bin/gmake --llvm-tools-dir /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./bin --lldb-obj-root /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/tools/lldb --lldb-libs-dir /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/./lib /home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/llvm-project/lldb/test/API/lang/c/fpeval -p TestFPEval.py
--
Exit Code: -11

Command Output (stdout):
--
lldb version 21.0.0git (https://github.com/llvm/llvm-project.git revision 420c056f853d9d5475fc98407ea99b67a11841eb)
  clang revision 420c056f853d9d5475fc98407ea99b67a11841eb
  llvm revision 420c056f853d9d5475fc98407ea99b67a11841eb
Skipping the following test categories: ['libc++', 'dsym', 'gmodules', 'debugserver', 'objc']

--
Command Output (stderr):
--
UNSUPPORTED: LLDB (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/bin/clang-aarch64) :: test_dsym (TestFPEval.FPEvalTestCase) (test case does not fall in any category of interest for this run) 
PASS: LLDB (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/bin/clang-aarch64) :: test_dwarf (TestFPEval.FPEvalTestCase)
PASS: LLDB (/home/tcwg-buildbot/worker/lldb-aarch64-ubuntu/build/bin/clang-aarch64) :: test_dwo (TestFPEval.FPEvalTestCase)
----------------------------------------------------------------------
Ran 3 tests in 1.012s

OK (skipped=1)

--

********************
PASS: lldb-api :: lang/c/inlines/TestRedefinitionsInInlines.py (725 of 2110)
PASS: lldb-api :: lang/c/anonymous/TestAnonymous.py (726 of 2110)
PASS: lldb-api :: lang/c/function_types/TestFunctionTypes.py (727 of 2110)
PASS: lldb-api :: lang/c/global_variables/TestGlobalVariables.py (728 of 2110)
PASS: lldb-api :: lang/c/parray_vrs_char_array/TestParrayVrsCharArrayChild.py (729 of 2110)
PASS: lldb-api :: lang/c/local_variables/TestLocalVariables.py (730 of 2110)
PASS: lldb-api :: lang/c/offsetof/TestOffsetof.py (731 of 2110)
PASS: lldb-api :: lang/c/record_decl_in_expr/TestRecordDeclInExpr.py (732 of 2110)
XFAIL: lldb-api :: lang/c/modules/TestCModules.py (733 of 2110)
PASS: lldb-api :: lang/c/non-mangled/TestCNonMangled.py (734 of 2110)

```

</details>

https://github.com/llvm/llvm-project/pull/132689