[llvm] [TableGen] Avoid assignmentInAssert warning (PR #139715)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `clang-cmake-x86_64-avx512-linux` running on `avx512-intel64` while building `llvm` at step 7 "ninja check 1".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/133/builds/16062

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

```
Step 7 (ninja check 1) failure: stage 1 checked (failure)
******************** TEST 'LLVM :: TableGen/GlobalISelCombinerEmitter/match-table-imms.td' FAILED ********************
Exit Code: 2

Command Output (stderr):
--
/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/llvm-tblgen -I /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/TableGen/GlobalISelCombinerEmitter/../../../include -gen-global-isel-combiner      -combiners=MyCombiner /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/TableGen/GlobalISelCombinerEmitter/match-table-imms.td |  /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/FileCheck /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/TableGen/GlobalISelCombinerEmitter/match-table-imms.td # RUN: at line 1
+ /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/FileCheck /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/TableGen/GlobalISelCombinerEmitter/match-table-imms.td
+ /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/llvm-tblgen -I /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/TableGen/GlobalISelCombinerEmitter/../../../include -gen-global-isel-combiner -combiners=MyCombiner /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/TableGen/GlobalISelCombinerEmitter/match-table-imms.td
llvm-tblgen: /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/utils/TableGen/GlobalISelCombinerEmitter.cpp:2615: virtual void {anonymous}::GICombinerEmitter::emitTestSimplePredicate(llvm::raw_ostream&): Assertion `ExpectedID == ID && "combine rules are not ordered!"' failed.
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/llvm-tblgen -I /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/TableGen/GlobalISelCombinerEmitter/../../../include -gen-global-isel-combiner -combiners=MyCombiner /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/TableGen/GlobalISelCombinerEmitter/match-table-imms.td
 #0 0x000000000075e981 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/llvm-tblgen+0x75e981)
 #1 0x000000000075c195 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #2 0x00007fa322e06db0 __restore_rt (/lib64/libc.so.6+0x59db0)
 #3 0x00007fa322e5342c __pthread_kill_implementation (/lib64/libc.so.6+0xa642c)
 #4 0x00007fa322e06d06 gsignal (/lib64/libc.so.6+0x59d06)
 #5 0x00007fa322dd97d3 abort (/lib64/libc.so.6+0x2c7d3)
 #6 0x00007fa322dd96fb _nl_load_domain.cold (/lib64/libc.so.6+0x2c6fb)
 #7 0x00007fa322dffc86 (/lib64/libc.so.6+0x52c86)
 #8 0x000000000062368e (/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/llvm-tblgen+0x62368e)
 #9 0x000000000047957f llvm::GlobalISelMatchTableExecutorEmitter::emitExecutorImpl(llvm::raw_ostream&, llvm::gi::MatchTable const&, llvm::ArrayRef<llvm::gi::LLTCodeGen>, llvm::ArrayRef<llvm::gi::RuleMatcher>, llvm::ArrayRef<llvm::Record const*>, llvm::ArrayRef<llvm::StringRef>, llvm::StringRef) (/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/llvm-tblgen+0x47957f)
#10 0x000000000063c0d2 EmitGICombiner(llvm::RecordKeeper const&, llvm::raw_ostream&) GlobalISelCombinerEmitter.cpp:0:0
#11 0x000000000079c19b llvm::TableGen::Emitter::ApplyCallback(llvm::RecordKeeper const&, llvm::raw_ostream&) (/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/llvm-tblgen+0x79c19b)
#12 0x000000000076a052 llvm::TableGenMain(char const*, std::function<bool (llvm::raw_ostream&, llvm::RecordKeeper const&)>) (/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/llvm-tblgen+0x76a052)
#13 0x0000000000445032 tblgen_main(int, char**) (/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/llvm-tblgen+0x445032)
#14 0x00007fa322df1e50 __libc_start_call_main (/lib64/libc.so.6+0x44e50)
#15 0x00007fa322df1efc __libc_start_main at GLIBC_2.2.5 (/lib64/libc.so.6+0x44efc)
#16 0x000000000040a765 _start (/localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/llvm-tblgen+0x40a765)
FileCheck error: '<stdin>' is empty.
FileCheck command line:  /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/stage1/bin/FileCheck /localdisk2/buildbot/llvm-worker/clang-cmake-x86_64-avx512-linux/llvm/llvm/test/TableGen/GlobalISelCombinerEmitter/match-table-imms.td

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/139715