[AutoUpgrade] Preserve attributes when upgrading named struct return

For example, if the argument has an alignment attribute, preserve it.

Author: nikic

llvm/lib/IR/AutoUpgrade.cpp

@@ -4330,7 +4330,8 @@ void llvm::UpgradeIntrinsicCall(CallBase *CI, Function *NewFn) {
              "Must have same number of elements");
 
       SmallVector<Value *> Args(CI->args());
-      Value *NewCI = Builder.CreateCall(NewFn, Args);
+      CallInst *NewCI = Builder.CreateCall(NewFn, Args);
+      NewCI->setAttributes(CI->getAttributes());
       Value *Res = PoisonValue::get(OldST);
       for (unsigned Idx = 0; Idx < OldST->getNumElements(); ++Idx) {
         Value *Elem = Builder.CreateExtractValue(NewCI, Idx);

llvm/test/Bitcode/intrinsics-struct-upgrade-attributes.ll

@@ -0,0 +1,18 @@
+; RUN: llvm-as < %s | llvm-dis | FileCheck %s
+
+%struct.__neon_int8x8x2_t = type { <8 x i8>, <8 x i8> }
+
+declare %struct.__neon_int8x8x2_t @llvm.aarch64.neon.ld2.v8i8.p0i8(i8*)
+
+; CHECK-LABEL: define %struct.__neon_int8x8x2_t @test_named_struct_return(ptr %A) {
+; CHECK:  %1 = call { <8 x i8>, <8 x i8> } @llvm.aarch64.neon.ld2.v8i8.p0(ptr align 16 %A)
+; CHECK:  %2 = extractvalue { <8 x i8>, <8 x i8> } %1, 0
+; CHECK:  %3 = insertvalue %struct.__neon_int8x8x2_t poison, <8 x i8> %2, 0
+; CHECK:  %4 = extractvalue { <8 x i8>, <8 x i8> } %1, 1
+; CHECK:  %5 = insertvalue %struct.__neon_int8x8x2_t %3, <8 x i8> %4, 1
+; CHECK:  ret %struct.__neon_int8x8x2_t %5
+
+define %struct.__neon_int8x8x2_t @test_named_struct_return(ptr %A) {
+  %val = call %struct.__neon_int8x8x2_t @llvm.aarch64.neon.ld2.v8i8.p0i8(ptr align 16 %A)
+  ret %struct.__neon_int8x8x2_t %val
+}