[binutils-gdb] Add test for following fork on position-independent executables

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 6295b6da16f73d5113d24424d1897edbce42bc6a ***

Author: Simon Marchi <simon.marchi@ericsson.com>
Branch: master
Commit: 6295b6da16f73d5113d24424d1897edbce42bc6a

Add test for following fork on position-independent executables

Commit

  b2e586e ("Defer breakpoint reset when cloning progspace for fork
  child")

fixed following fork childs when the executable is position-independent.
This patch adds a little test for it.

gdb/testsuite/ChangeLog:

	* gdb.base/pie-fork.c: New file.
	* gdb.base/pie-fork.exp: New file.