Since upstream gcc has recently increased the function alignment on
S390, the dw2-dir-file-name test case fails in the first
gdb_continue_to_breakpoint.  Indeed, the breakpoint is now placed into
the alignment gap *before* the actual function.

This happens because the test case declares the respective "*_start"
symbol as a "loose" label before the function definition, and the
compiler inserts the alignment between that label and the function
itself.

The "*_start" symbols were only necessary because FUNC made the
function static.  The fix makes the functions extern instead, thus
making the "*_start" labels unnecessary.

testsuite/
2014-01-10  Andreas Arnez  <arnez@linux.vnet.ibm.com>
	    Pedro Alves <palves@redhat.com>

	* gdb.dwarf2/dw2-dir-file-name.c (FUNC): Remove "*_start" symbol.
	Make "name" extern.
	* gdb.dwarf2/dw2-dir-file-name.exp (out_cu, out_line): Replace
	references to ${name}_start by references to ${name}.
[doc] Mention that "set environment" affects the shell too.

gdb/doc/
2014-01-10  Pedro Alves  <palves@redhat.com>

	* gdb.texinfo (Your Program's Environment) <set environment>:
	Mention the shell, and point at 'set exec-wrapper'.