[flang][acc] Fill-in name for privatized loop iv (llvm#126601)

When the loop induction variable implicit private clause was being
generated, the name was left empty. The intent is that the data clause
operation holds the source language variable name. Thus, add the missing
name now.

Author: razvanlupusoru

flang/lib/Lower/OpenACC.cpp

@@ -1803,6 +1803,7 @@ static void privatizeIv(Fortran::lower::AbstractConverter &converter,
       builder, recipeName, loc, ivValue.getType());
 
   std::stringstream asFortran;
+  asFortran << Fortran::lower::mangle::demangleName(toStringRef(sym.name()));
   auto op = createDataEntryOp<mlir::acc::PrivateOp>(
       builder, loc, ivValue, asFortran, {}, true, /*implicit=*/true,
       mlir::acc::DataClause::acc_private, ivValue.getType(),

flang/test/Lower/OpenACC/acc-loop.f90

@@ -321,8 +321,8 @@ subroutine sub1(i, j, k)
 ! CHECK: %[[DC_K:.*]] = fir.alloca i32 {bindc_name = "k"}
 ! CHECK: %[[DC_J:.*]] = fir.alloca i32 {bindc_name = "j"}
 ! CHECK: %[[DC_I:.*]] = fir.alloca i32 {bindc_name = "i"}
-! CHECK: %[[P_I:.*]] = acc.private varPtr(%[[DC_I]] : !fir.ref<i32>) -> !fir.ref<i32> {implicit = true, name = ""}
-! CHECK: %[[P_J:.*]] = acc.private varPtr(%[[DC_J]] : !fir.ref<i32>) -> !fir.ref<i32> {implicit = true, name = ""}
-! CHECK: %[[P_K:.*]] = acc.private varPtr(%[[DC_K]] : !fir.ref<i32>) -> !fir.ref<i32> {implicit = true, name = ""}
+! CHECK: %[[P_I:.*]] = acc.private varPtr(%[[DC_I]] : !fir.ref<i32>) -> !fir.ref<i32> {implicit = true, name = "i"}
+! CHECK: %[[P_J:.*]] = acc.private varPtr(%[[DC_J]] : !fir.ref<i32>) -> !fir.ref<i32> {implicit = true, name = "j"}
+! CHECK: %[[P_K:.*]] = acc.private varPtr(%[[DC_K]] : !fir.ref<i32>) -> !fir.ref<i32> {implicit = true, name = "k"}
 ! CHECK: acc.loop combined(parallel) private(@privatization_ref_i32 -> %[[P_I]] : !fir.ref<i32>, @privatization_ref_i32 -> %[[P_J]] : !fir.ref<i32>, @privatization_ref_i32 -> %[[P_K]] : !fir.ref<i32>) control(%{{.*}} : i32, %{{.*}} : i32, %{{.*}} : i32) = (%c1{{.*}}, %c1{{.*}}, %c1{{.*}} : i32, i32, i32) to (%c10{{.*}}, %c100{{.*}}, %c200{{.*}} : i32, i32, i32)  step (%c1{{.*}}, %c1{{.*}}, %c1{{.*}} : i32, i32, i32)
 ! CHECK: } attributes {inclusiveUpperbound = array<i1: true, true, true>}

flang/test/Lower/OpenACC/acc-private-unwrap-defaultbounds.f90

@@ -396,7 +396,7 @@ subroutine acc_private_use()
 ! CHECK: %[[I:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFacc_private_useEi"}
 ! CHECK: %[[DECL_I:.*]]:2 = hlfir.declare %0 {uniq_name = "_QFacc_private_useEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
 ! CHECK: acc.parallel
-! CHECK: %[[PRIV_I:.*]] = acc.private varPtr(%[[DECL_I]]#1 : !fir.ref<i32>) -> !fir.ref<i32> {implicit = true, name = ""}
+! CHECK: %[[PRIV_I:.*]] = acc.private varPtr(%[[DECL_I]]#1 : !fir.ref<i32>) -> !fir.ref<i32> {implicit = true, name = "i"}
 ! CHECK: %[[DECL_PRIV_I:.*]]:2 = hlfir.declare %[[PRIV_I]] {uniq_name = "_QFacc_private_useEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
 ! CHECK: acc.loop {{.*}} private(@privatization_ref_i32 -> %[[PRIV_I]] : !fir.ref<i32>) control(%[[IV0:.*]] : i32) = (%c1{{.*}} : i32) to (%c10{{.*}} : i32) step (%c1{{.*}} : i32)
 ! CHECK:   fir.store %[[IV0]] to %[[DECL_PRIV_I]]#0 : !fir.ref<i32>

flang/test/Lower/OpenACC/acc-private.f90

@@ -384,7 +384,7 @@ subroutine acc_private_use()
 ! CHECK: %[[I:.*]] = fir.alloca i32 {bindc_name = "i", uniq_name = "_QFacc_private_useEi"}
 ! CHECK: %[[DECL_I:.*]]:2 = hlfir.declare %0 {uniq_name = "_QFacc_private_useEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
 ! CHECK: acc.parallel
-! CHECK: %[[PRIV_I:.*]] = acc.private varPtr(%[[DECL_I]]#1 : !fir.ref<i32>) -> !fir.ref<i32> {implicit = true, name = ""}
+! CHECK: %[[PRIV_I:.*]] = acc.private varPtr(%[[DECL_I]]#1 : !fir.ref<i32>) -> !fir.ref<i32> {implicit = true, name = "i"}
 ! CHECK: %[[DECL_PRIV_I:.*]]:2 = hlfir.declare %[[PRIV_I]] {uniq_name = "_QFacc_private_useEi"} : (!fir.ref<i32>) -> (!fir.ref<i32>, !fir.ref<i32>)
 ! CHECK: acc.loop {{.*}} private(@privatization_ref_i32 -> %[[PRIV_I]] : !fir.ref<i32>) control(%[[IV0:.*]] : i32) = (%c1{{.*}} : i32) to (%c10{{.*}} : i32) step (%c1{{.*}} : i32)
 ! CHECK:   fir.store %[[IV0]] to %[[DECL_PRIV_I]]#0 : !fir.ref<i32>