nptl: restore .interp section in libpthread.so

In commit 02657da2cf4457804ed938ee08b8316249126444, .interp section
was removed from libpthread.so.  This led to an error:

  $ /lib64/libpthread.so.0
  Native POSIX Threads Library by Ulrich Drepper et al
  Copyright (C) 2015 Free Software Foundation, Inc.
  This is free software; see the source for copying conditions.
  There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A
  PARTICULAR PURPOSE.
  Forced unwind support included.
  Segmentation fault

  (gdb) bt
  #0  0x00000000000055a6 in _exit@plt ()

Unfortunately, there is no way to add a regression test for the bug
because .interp specifies the path to dynamic linker of the target
system.

[BZ #18479]
* nptl/pt-interp.c: New file.
* nptl/Makefile (libpthread-routines, libpthread-shared-only-routines):
Add pt-interp.
[$(build-shared) = yes] ($(objpfx)pt-interp.os): Depend on
$(common-objpfx)runtime-linker.h.

1 files changed, 1 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index 221ec2f..218bf3a 100644
--- a/NEWS
+++ b/NEWS
@@ -20,7 +20,7 @@ Version 2.22
   18111, 18116, 18125, 18128, 18138, 18185, 18196, 18197, 18206, 18210,
   18211, 18217, 18220, 18221, 18234, 18244, 18247, 18287, 18319, 18324,
   18333, 18346, 18397, 18409, 18410, 18412, 18418, 18422, 18434, 18444,
-  18468, 18469, 18470, 18483, 18495, 18496, 18497, 18498, 18507.
+  18468, 18469, 18470, 18479, 18483, 18495, 18496, 18497, 18498, 18507.
 
 * Cache information can be queried via sysconf() function on s390 e.g. with
   _SC_LEVEL1_ICACHE_SIZE as argument.