[CIR][Lowering][NFC] Expose cir::prepareTypeConverter()

Export this function so it can be used by other projects.

Author: keryell

clang/include/clang/CIR/LowerToMLIR.h

@@ -16,6 +16,7 @@ namespace cir {
 
 void populateCIRLoopToSCFConversionPatterns(mlir::RewritePatternSet &patterns,
                                             mlir::TypeConverter &converter);
+mlir::TypeConverter prepareTypeConverter();
 } // namespace cir
 
 #endif // CLANG_CIR_LOWERTOMLIR_H_

clang/lib/CIR/Lowering/ThroughMLIR/LowerCIRToMLIR.cpp

@@ -1368,7 +1368,7 @@ void populateCIRToMLIRConversionPatterns(mlir::RewritePatternSet &patterns,
                                                         patterns.getContext());
 }
 
-static mlir::TypeConverter prepareTypeConverter() {
+mlir::TypeConverter prepareTypeConverter() {
   mlir::TypeConverter converter;
   converter.addConversion([&](cir::PointerType type) -> mlir::Type {
     auto ty = convertTypeForMemory(converter, type.getPointee());