mpi_f08: fix MPI_BUFFER_DETACH interfaces

Add an mpi_f08-specific implementation for MPI_BUFFER_DETACH.

Per MPI-3.1:3.6, p45, the buffer argument is ignored in
MPI_BUFFER_DETACH for mpif.h and the mpi module.  But in the mpi_f08
module, the buffer argument is treated like it is in the C binding.

ompi/mpi/fortran/mpif-h/buffer_detach_f.c

@@ -10,7 +10,7 @@
  * Copyright (c) 2004-2005 The Regents of the University of California.
  *                         All rights reserved.
  * Copyright (c) 2007      Sun Microsystems, Inc.  All rights reserved.
- * Copyright (c) 2011-2012 Cisco Systems, Inc.  All rights reserved.
+ * Copyright (c) 2011-2015 Cisco Systems, Inc.  All rights reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -65,14 +65,17 @@ OMPI_GENERATE_F77_BINDINGS (MPI_BUFFER_DETACH,
 #include "ompi/mpi/fortran/mpif-h/profile/defines.h"
 #endif
 
+/*
+ * MPI-3.1 section 3.6, page 45, states that the mpif.h and mpi module
+ * interfaces for MPI_BUFFER_DETACH ignore the buffer argument.
+ * Therefore, for the mpif.h and mpi module interfaces, we use a dummy
+ * variable and leave the value handed in alone.
+ *
+ * The mpi_f08 implementation for MPI_BUFFER_DETACH is a separate
+ * routine -- see below.
+ */
 void ompi_buffer_detach_f(char *buffer, MPI_Fint *size, MPI_Fint *ierr)
 {
-    /*
-     * It does not make sense in fortran to return a pointer
-     * here as the user may get a behavior that is unexpected.
-     * Therefore, we use a dummy variable and leave the value
-     * handed in alone.
-     */
     int c_ierr;
     void *dummy;
     OMPI_SINGLE_NAME_DECL(size);
@@ -83,3 +86,25 @@ void ompi_buffer_detach_f(char *buffer, MPI_Fint *size, MPI_Fint *ierr)
         OMPI_SINGLE_INT_2_FINT(size);
     }
 }
+
+/*
+ * Per above, this is the mpi_f08 module implementation of
+ * MPI_BUFFER_DETACH.  It handles the buffer arugment just like the C
+ * binding.
+ */
+void ompi_buffer_detach_f08(char *buffer, MPI_Fint *size, MPI_Fint *ierr)
+{
+    int c_ierr;
+    void *dummy;
+
+    OMPI_SINGLE_NAME_DECL(size);
+    c_ierr = MPI_Buffer_detach(&dummy, OMPI_SINGLE_NAME_CONVERT(size));
+    if (NULL != ierr) {
+        *(void **)buffer = dummy;
+        *ierr = OMPI_INT_2_FINT(c_ierr);
+    }
+
+    if (MPI_SUCCESS == c_ierr) {
+        OMPI_SINGLE_INT_2_FINT(size);
+    }
+}

ompi/mpi/fortran/use-mpi-f08/mpi-f-interfaces-bind.h

@@ -189,8 +189,11 @@ subroutine ompi_buffer_attach_f(buffer,size,ierror) &
    INTEGER, INTENT(OUT) :: ierror
 end subroutine ompi_buffer_attach_f
 
+! Note that we have an F08-specific C implementation function for
+! MPI_BUFFER_DETACH (i.e., it is different than the mpif.h / mpi
+! module C implementation function).
 subroutine ompi_buffer_detach_f(buffer_addr,size,ierror) &
-   BIND(C, name="ompi_buffer_detach_f")
+   BIND(C, name="ompi_buffer_detach_f08")
    USE, INTRINSIC ::  ISO_C_BINDING, ONLY : C_PTR
    implicit none
    TYPE(C_PTR), INTENT(OUT) ::  buffer_addr

ompi/mpi/fortran/use-mpi-f08/pmpi-f-interfaces-bind.h

@@ -91,8 +91,16 @@ subroutine pompi_buffer_attach_f(buffer,size,ierror) &
    INTEGER, INTENT(OUT) :: ierror
 end subroutine pompi_buffer_attach_f
 
+! Note that we have an F08-specific C implementation function for
+! PMPI_BUFFER_DETACH (i.e., it is different than the mpif.h / mpi
+! module C implementation function).
+!
+! Note, too, we don't need a "p" version of the C implementation
+! function -- Fortran's interfaces provide MPI_ and PMPI_ names for
+! us; they can just both be bound to the same back-end
+! ompi_buffer_detach_f08 C function.
 subroutine pompi_buffer_detach_f(buffer_addr,size,ierror) &
-   BIND(C, name="pompi_buffer_detach_f")
+   BIND(C, name="ompi_buffer_detach_f08")
    implicit none
    OMPI_FORTRAN_IGNORE_TKR_TYPE, INTENT(IN) :: buffer_addr
    INTEGER, INTENT(OUT) :: size