Use the 64-bit ABI for offset and inode types

32-bit offsets (__OFF_T_TYPE) and file serial numbers (__INO_T_TYPE) are
deprecated for new 32-bit architectures.

This solution makes compulsory the 64-bit-like ABI for all RISC-V flavors, by:

a) creating an arch-specific file that includes "linux/generic/bits/typesizes.h"

b) overriding the macros so they match __INO64_T_TYPE and __OFF64_T_TYPE, and
   setting __INO_T_MATCHES_INO64_T and __OFF_T_MATCHES_OFF64_T accordingly

glibc/sysdeps/unix/sysv/linux/riscv/bits/typesizes.h

@@ -0,0 +1,33 @@
+/* bits/typesizes.h -- underlying types for *_t.  Based on generic Linux
+   ABI for Linux/RISC-V.
+
+   Copyright (C) 2011-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _BITS_TYPES_H
+# error "Never include <bits/typesizes.h> directly; use <sys/types.h> instead."
+#endif
+
+/* Include the header for linux/generic, to get the same values by default */
+#include <sysdeps/unix/sysv/linux/generic/bits/typesizes.h>
+
+/* Overrides -- RISC-V 32 and 64-bits to use the 64-bit ABI.  32-bit offsets and
+   file (inode) serial numbers are deprecated for new 32-bit architectures */
+#define __INO_T_TYPE		__UQUAD_TYPE
+#define __OFF_T_TYPE		__SQUAD_TYPE
+#define __INO_T_MATCHES_INO64_T	1
+#define __OFF_T_MATCHES_OFF64_T	1