[flang][OpenMP] Fix threadprivate pointer variable in common block (llvm#131888)

Fixes llvm#112538

The problem was that the host associated symbol for the threadprivate
variable doesn't have all of the symbol attributes (e.g. POINTER). This
caused the lowering code to generate the wrong type, eventually hitting
an assertion.

Author: tblah

flang/lib/Lower/OpenMP/OpenMP.cpp

@@ -763,7 +763,8 @@ static void threadPrivatizeVars(lower::AbstractConverter &converter,
         commonSyms.insert(common);
       }
       symThreadprivateValue = lower::genCommonBlockMember(
-          converter, currentLocation, *sym, commonThreadprivateValue);
+          converter, currentLocation, sym->GetUltimate(),
+          commonThreadprivateValue);
     } else {
       symThreadprivateValue = genThreadprivateOp(*sym);
     }

flang/test/Lower/OpenMP/threadprivate-common-block-pointer.f90

@@ -0,0 +1,31 @@
+! Simple test for lowering of OpenMP Threadprivate Directive with a pointer var
+! from a common block.
+
+!RUN: %flang_fc1 -emit-hlfir -fopenmp %s -o - | FileCheck %s
+!RUN: bbc -hlfir -emit-hlfir -fopenmp %s -o - | FileCheck %s
+
+! Regression test for a compiler crash
+
+module mmm
+integer,pointer::nam1
+common /com1/nam1,nam2
+!$omp threadprivate(/com1/)
+end
+use mmm
+!$omp parallel copyin(nam1)
+!$omp end parallel
+end
+
+
+! CHECK-LABEL:   fir.global common @com1_(dense<0> : vector<28xi8>) {alignment = 8 : i64} : !fir.array<28xi8>
+
+! CHECK-LABEL:   func.func @_QQmain() {
+! CHECK:           %[[VAL_0:.*]] = fir.address_of(@com1_) : !fir.ref<!fir.array<28xi8>>
+! CHECK:           omp.parallel {
+! CHECK:             %[[VAL_17:.*]] = omp.threadprivate %[[VAL_0]] : !fir.ref<!fir.array<28xi8>> -> !fir.ref<!fir.array<28xi8>>
+! CHECK:             %[[VAL_18:.*]] = fir.convert %[[VAL_17]] : (!fir.ref<!fir.array<28xi8>>) -> !fir.ref<!fir.array<?xi8>>
+! CHECK:             %[[VAL_19:.*]] = arith.constant 0 : index
+! CHECK:             %[[VAL_20:.*]] = fir.coordinate_of %[[VAL_18]], %[[VAL_19]] : (!fir.ref<!fir.array<?xi8>>, index) -> !fir.ref<i8>
+! CHECK:             %[[VAL_21:.*]] = fir.convert %[[VAL_20]] : (!fir.ref<i8>) -> !fir.ref<!fir.box<!fir.ptr<i32>>>
+! CHECK:             %[[VAL_22:.*]]:2 = hlfir.declare %[[VAL_21]] {fortran_attrs = #{{.*}}<pointer>, uniq_name = "_QMmmmEnam1"} : (!fir.ref<!fir.box<!fir.ptr<i32>>>) -> (!fir.ref<!fir.box<!fir.ptr<i32>>>, !fir.ref<!fir.box<!fir.ptr<i32>>>)
+