Revert "[mlir][Affine] Handle null parent op in getAffineParallelInductionVarOwner (#142025)"

This reverts commit c3746ff.

This breaks build with BUILD_SHARED_LIBS=ON.

```
/usr/bin/ld: CMakeFiles/MLIRTestMemRefToLLVMWithTransforms.dir/TestMemRefToLLVMWithTransforms.cpp.o: in function `(anonymous namespace)::TestMemRefToLLVMWithTransforms::runOnOperation()':
TestMemRefToLLVMWithTransforms.cpp:(.text._ZN12_GLOBAL__N_130TestMemRefToLLVMWithTransforms14runOnOperationEv+0x68): undefined reference to `mlir::LowerToLLVMOptions::LowerToLLVMOptions(mlir::MLIRContext*)'
/usr/bin/ld: TestMemRefToLLVMWithTransforms.cpp:[ 88%] Built target CodeGenTests
(.text._ZN12_GLOBAL__N_130TestMemRefToLLVMWithTransforms14runOnOperationEvmake[2]: Leaving directory '/work2/kparzysz/git/llvm.org/b/x86'
+0x80): undefined reference to `mlir::LLVMTypeConverter::LLVMTypeConverter(mlir::MLIRContext*, mlir::LowerToLLVMOptions const&, mlir::DataLayoutAnalysis const*)'
/usr/bin/ld: TestMemRefToLLVMWithTransforms.cpp:(.text._ZN12_GLOBAL__N_130TestMemRefToLLVMWithTransforms14runOnOperationEv+0x143): undefined reference to `mlir::populateFuncToLLVMConversionPatterns(mlir::LLVMTypeConverter const&, mlir::RewritePatternSet&, mlir::SymbolTable const*)'
/usr/bin/ld: TestMemRefToLLVMWithTransforms.cpp:(.text._ZN12_GLOBAL__N_130TestMemRefToLLVMWithTransforms14runOnOperationEv+0x174): undefined reference to `mlir::LLVMConversionTarget::LLVMConversionTarget(mlir::MLIRContext&)'
```

Author: kparzysz

mlir/lib/Dialect/Affine/IR/AffineOps.cpp

@@ -2667,7 +2667,7 @@ AffineParallelOp mlir::affine::getAffineParallelInductionVarOwner(Value val) {
   if (!ivArg || !ivArg.getOwner())
     return nullptr;
   Operation *containingOp = ivArg.getOwner()->getParentOp();
-  auto parallelOp = dyn_cast_if_present<AffineParallelOp>(containingOp);
+  auto parallelOp = dyn_cast<AffineParallelOp>(containingOp);
   if (parallelOp && llvm::is_contained(parallelOp.getIVs(), val))
     return parallelOp;
   return nullptr;

mlir/test/Conversion/MemRefToLLVM/memref-to-llvm-with-transforms.mlir

@@ -1,5 +1,4 @@
 add_subdirectory(ConvertToSPIRV)
 add_subdirectory(FuncToLLVM)
 add_subdirectory(MathToVCIX)
-add_subdirectory(MemRefToLLVM)
 add_subdirectory(VectorToSPIRV)

mlir/test/lib/Conversion/CMakeLists.txt

@@ -28,7 +28,6 @@ if(MLIR_INCLUDE_TESTS)
     MLIRMathTestPasses
     MLIRTestMathToVCIX
     MLIRMemRefTestPasses
-    MLIRTestMemRefToLLVMWithTransforms
     MLIRMeshTest
     MLIRNVGPUTestPasses
     MLIRSCFTestPasses

mlir/test/lib/Conversion/MemRefToLLVM/CMakeLists.txt

@@ -130,7 +130,6 @@ void registerTestMathToVCIXPass();
 void registerTestIrdlTestDialectConversionPass();
 void registerTestMemRefDependenceCheck();
 void registerTestMemRefStrideCalculation();
-void registerTestMemRefToLLVMWithTransforms();
 void registerTestMeshReshardingSpmdizationPass();
 void registerTestMeshSimplificationsPass();
 void registerTestMultiBuffering();
@@ -276,7 +275,6 @@ void registerTestPasses() {
   mlir::test::registerTestMathToVCIXPass();
   mlir::test::registerTestMemRefDependenceCheck();
   mlir::test::registerTestMemRefStrideCalculation();
-  mlir::test::registerTestMemRefToLLVMWithTransforms();
   mlir::test::registerTestMeshReshardingSpmdizationPass();
   mlir::test::registerTestMeshSimplificationsPass();
   mlir::test::registerTestMultiBuffering();