[mlir] -inline implement handleTerminator bug report

git version: 81a8c66fdc96a7bf6927bf3f88d4b2e24a5c71e7

system: `Ubuntu 18.04.6 LTS`

reproduce with: `mlir-opt -inline a.mlir`

a.mlir:

```mlir
module {
llvm.func @atanh_vec_f32(%arg0: vector<8xf32>) {
%0 = math.atanh %arg0 : vector<8xf32>
vector.yield %arg0 : vector<8xf32>
}
llvm.func @_mlir_ciface_atanh_vec_f32(%arg0: vector<8xf32>) attributes {llvm.emit_c_interface} {
llvm.call @atanh_vec_f32(%arg0) : (vector<8xf32>) -> ()
llvm.return
}
}

```

stack trace:

```
must implement handleTerminator in the case of one inlined block
UNREACHABLE executed at /data/szy/MLIR/llvm-release/llvm-project/build/tools/mlir/include/mlir/Transforms/DialectInlinerInterface.h.inc:82!
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace and instructions to reproduce the bug.
Stack dump:
0. Program arguments: /data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt -inline 74.mlir
#0 0x0000561f7012a0c8 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0x20360c8)
#1 0x0000561f70126f61 llvm::sys::RunSignalHandlers() (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0x2032f61)
#2 0x0000561f7012b1e6 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
#3 0x00007f6dcc2a2420 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x14420)
#4 0x00007f6dcb8df00b raise /build/glibc-LcI20x/glibc-2.31/signal/../sysdeps/unix/sysv/linux/raise.c:51:1
#5 0x00007f6dcb8be859 abort /build/glibc-LcI20x/glibc-2.31/stdlib/abort.c:81:7
#6 0x0000561f7011057f (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0x201c57f)
#7 0x0000561f720b9779 (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0x3fc5779)
#8 0x0000561f78a980ef inlineRegionImpl(mlir::InlinerInterface&, llvm::function_ref, mlir::Region*, mlir::Block*, llvm::ilist_iterator, false, false>, mlir::IRMapping&, mlir::ValueRange, mlir::TypeRange, std::optional, bool, mlir::CallOpInterface) InliningUtils.cpp:0:0
#9 0x0000561f78a98e3a mlir::inlineCall(mlir::InlinerInterface&, llvm::function_ref, mlir::CallOpInterface, mlir::CallableOpInterface, mlir::Region*, bool) (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0xa9a4e3a)
#10 0x0000561f78a94a99 mlir::Inliner::Impl::inlineSCC((anonymous namespace)::InlinerInterfaceImpl&, (anonymous namespace)::CGUseList&, (anonymous namespace)::CallGraphSCC&, mlir::MLIRContext*) Inliner.cpp:0:0
#11 0x0000561f78a8e85a mlir::Inliner::doInlining() (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0xa99a85a)
#12 0x0000561f78a13f3c (anonymous namespace)::InlinerPass::runOnOperation() InlinerPass.cpp:0:0
#13 0x0000561f78b12662 mlir::detail::OpToOpPassAdaptor::run(mlir::Pass*, mlir::Operation*, mlir::AnalysisManager, bool, unsigned int) (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0xaa1e662)
#14 0x0000561f78b134a4 mlir::detail::OpToOpPassAdaptor::runPipeline(mlir::OpPassManager&, mlir::Operation*, mlir::AnalysisManager, bool, unsigned int, mlir::PassInstrumentor*, mlir::PassInstrumentation::PipelineParentInfo const*) (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0xaa1f4a4)
#15 0x0000561f78b1a3ba mlir::PassManager::runPasses(mlir::Operation*, mlir::AnalysisManager) (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0xaa263ba)
#16 0x0000561f78b19cef mlir::PassManager::run(mlir::Operation*) (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0xaa25cef)
#17 0x0000561f701d93c0 performActions(llvm::raw_ostream&, std::shared_ptr const&, mlir::MLIRContext*, mlir::MlirOptMainConfig const&) MlirOptMain.cpp:0:0
#18 0x0000561f701d85f6 llvm::LogicalResult llvm::function_ref>, llvm::MemoryBufferRef const&, llvm::raw_ostream&)>::callback_fn>, mlir::DialectRegistry&, mlir::MlirOptMainConfig const&)::$_0>(long, std::unique_ptr>, llvm::MemoryBufferRef const&, llvm::raw_ostream&) MlirOptMain.cpp:0:0
#19 0x0000561f78e65e55 mlir::splitAndProcessBuffer(std::unique_ptr>, llvm::function_ref>, llvm::MemoryBufferRef const&, llvm::raw_ostream&)>, llvm::raw_ostream&, llvm::StringRef, llvm::StringRef) (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0xad71e55)
#20 0x0000561f701cf656 mlir::MlirOptMain(llvm::raw_ostream&, std::unique_ptr>, mlir::DialectRegistry&, mlir::MlirOptMainConfig const&) (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0x20db656)
#21 0x0000561f701cfa35 mlir::MlirOptMain(int, char**, llvm::StringRef, llvm::StringRef, mlir::DialectRegistry&) (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0x20dba35)
#22 0x0000561f701cfd95 mlir::MlirOptMain(int, char**, llvm::StringRef, mlir::DialectRegistry&) (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0x20dbd95)
#23 0x0000561f7010fb52 main (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0x201bb52)
#24 0x00007f6dcb8c0083 __libc_start_main /build/glibc-LcI20x/glibc-2.31/csu/../csu/libc-start.c:342:3
#25 0x0000561f7010f68e _start (/data/szy/MLIR/llvm-release/llvm-project/build/bin/mlir-opt+0x201b68e)
Aborted (core dumped)
```

Run mlir-opt -inline on the supplied a.mlir reproducer and inspect the assertion in DialectInlinerInterface.h.inc, then trace the inlining path through InliningUtils.cpp and Inliner.cpp. Add a regression test for this reproducer and verify that the inline pass completes without the handleTerminator crash.

Written by the indexing model from the issue text.