[CIR] Infer MLIR context in type builders when possible (llvm#136362)

This mirrors incubator changes from
llvm/clangir#1570

Author: xlauko

clang/include/clang/CIR/Dialect/IR/CIRTypes.td

@@ -294,6 +294,14 @@ def CIR_ArrayType : CIR_Type<"Array", "array",
 
   let parameters = (ins "mlir::Type":$eltType, "uint64_t":$size);
 
+  let builders = [
+    TypeBuilderWithInferredContext<(ins
+      "mlir::Type":$eltType, "uint64_t":$size
+    ), [{
+        return $_get(eltType.getContext(), eltType, size);
+    }]>,
+  ];
+
   let assemblyFormat = [{
     `<` $eltType `x` $size `>`
   }];

clang/lib/CIR/CodeGen/CIRGenExprConstant.cpp

@@ -206,8 +206,7 @@ emitArrayConstant(CIRGenModule &cgm, mlir::Type desiredType,
       eles.push_back(element);
 
     return cir::ConstArrayAttr::get(
-        cir::ArrayType::get(builder.getContext(), commonElementType,
-                            arrayBound),
+        cir::ArrayType::get(commonElementType, arrayBound),
         mlir::ArrayAttr::get(builder.getContext(), eles));
   }
 

clang/lib/CIR/CodeGen/CIRGenRecordLayoutBuilder.cpp

@@ -102,8 +102,7 @@ struct CIRRecordLowering final {
     mlir::Type type = getCharType();
     return numberOfChars == CharUnits::One()
                ? type
-               : cir::ArrayType::get(type.getContext(), type,
-                                     numberOfChars.getQuantity());
+               : cir::ArrayType::get(type, numberOfChars.getQuantity());
   }
 
   mlir::Type getStorageType(const FieldDecl *fieldDecl) {

clang/lib/CIR/CodeGen/CIRGenTypes.cpp

@@ -395,8 +395,7 @@ mlir::Type CIRGenTypes::convertType(QualType type) {
   case Type::ConstantArray: {
     const ConstantArrayType *arrTy = cast<ConstantArrayType>(ty);
     mlir::Type elemTy = convertTypeForMem(arrTy->getElementType());
-    resultType = cir::ArrayType::get(builder.getContext(), elemTy,
-                                     arrTy->getSize().getZExtValue());
+    resultType = cir::ArrayType::get(elemTy, arrTy->getSize().getZExtValue());
     break;
   }