[flang][openacc] Fix unparsing of bind clause on acc routine

[clementval]

Summary

unparsing for the bind clause was adding extra
parenthesis. This patch fixes that.

flang/lib/Parser/unparse.cpp

 #define GEN_FLANG_CLAUSE_UNPARSE
 #include "llvm/Frontend/OpenACC/ACC.inc"
   void Unparse(const AccObjectListWithModifier &x) {
     Walk(std::get<std::optional<AccDataModifier>>(x.t), ":");
     Walk(std::get<AccObjectList>(x.t));
   }
   void Unparse(const AccBindClause &x) {
     common::visit(common::visitors{
-                      [&](const Name &y) { Put('('), Walk(y), Put(')'); },
-                      [&](const ScalarDefaultCharExpr &y) {
-                        Put('('), Walk(y), Put(')');
-                      },
+                      [&](const Name &y) { Walk(y); },
+                      [&](const ScalarDefaultCharExpr &y) { Walk(y); },
                   },
         x.u);
   }
   void Unparse(const AccDefaultClause &x) {
     switch (x.v) {
     case llvm::acc::DefaultValue::ACC_Default_none:
       Put("NONE");
       break;

flang/test/Parser/acc-unparse.f90

! CHECK: !$ACC LOOP GANG(STATIC:*)
 
   !$acc loop gang(static:gangStatic, dim: gangDim)
   do i = 1, 10
     a(i) = i
   end do
 ! CHECK: !$ACC LOOP GANG(STATIC:gangstatic,DIM:gangdim)
 
 end subroutine
+
+subroutine routine1()
+  !$acc routine bind("routine1_")
+! CHECK: !$ACC ROUTINE BIND("routine1_")
+end subroutine
+
+subroutine routine2()
+  !$acc routine(routine2) bind(routine2)
+! CHECK: !$ACC ROUTINE(routine2) BIND(routine2)
+end subroutine