Rollback of PR #1349: direct_mmap: Use off_t on linux...

PiperOrigin-RevId: 501014555
Change-Id: Ie204d307a4e537935a04c0f23bb13532e3c84bc8

absl/base/internal/direct_mmap.h

diff --git a/absl/base/internal/direct_mmap.h b/absl/base/internal/direct_mmap.h
index 14efc63..815b8d2 100644
--- a/absl/base/internal/direct_mmap.h
+++ b/absl/base/internal/direct_mmap.h
@@ -72,7 +72,7 @@
 // Platform specific logic extracted from
 // https://chromium.googlesource.com/linux-syscall-support/+/master/linux_syscall_support.h
 inline void* DirectMmap(void* start, size_t length, int prot, int flags, int fd,
-                        off_t offset) noexcept {
+                        off64_t offset) noexcept {
 #if defined(__i386__) || defined(__ARM_ARCH_3__) || defined(__ARM_EABI__) || \
     defined(__m68k__) || defined(__sh__) ||                                  \
     (defined(__hppa__) && !defined(__LP64__)) ||                             \
@@ -101,7 +101,8 @@
                  static_cast<size_t>(offset / pagesize));
 #else
   return reinterpret_cast<void*>(
-      syscall(SYS_mmap2, start, length, prot, flags, fd, offset / pagesize));
+      syscall(SYS_mmap2, start, length, prot, flags, fd,
+              static_cast<off_t>(offset / pagesize)));
 #endif
 #elif defined(__s390x__)
   // On s390x, mmap() arguments are passed in memory.