[flang] Retrieve rank before updating the pointer

The code is iterating on the rank of the pointer to set the bounds.
If the rank is retrieved after the `pointer = target` it does not
reflect the actual rank of the pointer.

This could happen in code like the following:

```
type t1
  integer :: a
end type

type(t), pointer :: p(:)
class(t), pointer :: q(:,:)
q(0:1,-2:2) => p(10:1:-1)
```

Reviewed By: klausler

Differential Revision: https://reviews.llvm.org/D139327

diff --git a/flang/runtime/pointer.cpp b/flang/runtime/pointer.cpp
index 843f916..1ce9139 100644 (file)
--- a/flang/runtime/pointer.cpp
+++ b/flang/runtime/pointer.cpp
@@ -87,9 +87,9 @@ void RTNAME(PointerAssociateLowerBounds)(Descriptor &pointer,
 void RTNAME(PointerAssociateRemapping)(Descriptor &pointer,
     const Descriptor &target, const Descriptor &bounds, const char *sourceFile,
     int sourceLine) {
+  int rank{pointer.rank()};
   pointer = target;
   pointer.raw().attribute = CFI_attribute_pointer;
-  int rank{pointer.rank()};
   Terminator terminator{sourceFile, sourceLine};
   SubscriptValue byteStride{/*captured from first dimension*/};
   std::size_t boundElementBytes{bounds.ElementBytes()};