[flang] Do not include dangling ac-implied-do-index in folded shape inquiry

[jeanPerier]

Summary

The current code was replacing inquiry to array constructor whose
ac-value shape depends on ac-implied-do-index with an expression
using the ac-implied-do-index without the implied-do (folding the
first case added in the test as in the second case with a regular
symbol).

flang/include/flang/Evaluate/shape.h

return common::visit(
             },
             [&](const ImpliedDo<T> &ido) -> MaybeExtentExpr {
               // Don't be heroic and try to figure out triangular implied DO
               // nests.
               if (!ContainsAnyImpliedDoIndex(ido.lower()) &&
                   !ContainsAnyImpliedDoIndex(ido.upper()) &&
                   !ContainsAnyImpliedDoIndex(ido.stride())) {
                 if (auto nValues{GetArrayConstructorExtent(ido.values())}) {
+                  if (!ContainsAnyImpliedDoIndex(*nValues)) {
                     return std::move(*nValues) *
                         CountTrips(ido.lower(), ido.upper(), ido.stride());
                   }
                 }
+              }
               return std::nullopt;
             },
         },
         value.u);
   }
 
   template <typename T>
   MaybeExtentExpr GetArrayConstructorExtent(

flang/test/Evaluate/rewrite01.f90

interface
     function return_allocatable()
      real, allocatable :: return_allocatable(:)
     end function
   end interface
   !CHECK: PRINT *, size([REAL(4)::return_allocatable(),return_allocatable()])
   print *, size([return_allocatable(), return_allocatable()])
 end subroutine
 
+!CHECK-LABEL: array_ctor_implied_do_index
+subroutine array_ctor_implied_do_index(x, j)
+  integer :: x(:)
+  integer(8) :: j
+  !CHECK: PRINT *, size([INTEGER(4)::(x(1_8:i:1_8),INTEGER(8)::i=1_8,2_8,1_8)])
+  print *, size([(x(1:i), integer(8)::i=1,2)])
+  !CHECK: PRINT *, int(0_8+2_8*(0_8+max((j-1_8+1_8)/1_8,0_8)),kind=4)
+  print *, size([(x(1:j), integer(8)::i=1,2)])
+end subroutine
+
 end module