[MLIR][ControlFlowToLLVM] Remove typed pointer support (#70733)

This commit removes the support for lowering ControlFlow to LLVM dialect
with typed pointers. Typed pointers have been deprecated for a while now
and it's planned to soon remove them from the LLVM dialect.

Related PSA:
https://discourse.llvm.org/t/psa-removal-of-typed-pointers-from-the-llvm-dialect/74502

Author: Dinistro

mlir/include/mlir/Conversion/Passes.td

@@ -293,10 +293,7 @@ def ConvertControlFlowToLLVMPass : Pass<"convert-cf-to-llvm", "ModuleOp"> {
   let options = [
     Option<"indexBitwidth", "index-bitwidth", "unsigned",
            /*default=kDeriveIndexBitwidthFromDataLayout*/"0",
-           "Bitwidth of the index type, 0 to use size of machine word">,
-    Option<"useOpaquePointers", "use-opaque-pointers", "bool",
-                   /*default=*/"true", "Generate LLVM IR using opaque pointers "
-                   "instead of typed pointers">,
+           "Bitwidth of the index type, 0 to use size of machine word">
   ];
 }
 

mlir/lib/Conversion/ControlFlowToLLVM/ControlFlowToLLVM.cpp

@@ -236,7 +236,6 @@ struct ConvertControlFlowToLLVM
     LowerToLLVMOptions options(&getContext());
     if (indexBitwidth != kDeriveIndexBitwidthFromDataLayout)
       options.overrideIndexBitwidth(indexBitwidth);
-    options.useOpaquePointers = useOpaquePointers;
 
     LLVMTypeConverter converter(&getContext(), options);
     mlir::cf::populateControlFlowToLLVMConversionPatterns(converter, patterns);

mlir/test/Conversion/ControlFlowToLLVM/assert.mlir

@@ -1,4 +1,4 @@
-// RUN: mlir-opt %s -convert-cf-to-llvm='use-opaque-pointers=1' | FileCheck %s
+// RUN: mlir-opt %s -convert-cf-to-llvm | FileCheck %s
 
 // Same below, but using the `ConvertToLLVMPatternInterface` entry point
 // and the generic `convert-to-llvm` pass.