[PATCH] Fix spurious FAILs with examine-backward.exp

[Andreas Arnez <arnez@linux.vnet.ibm.com>]

The test case examine-backward.exp issues the command "x/-s" after the end
of the first string in TestStrings, but without making sure that this
string is preceded by a string terminator.  Thus GDB may spuriously print
some random characters from before that string, and then the test fails.

This patch assures that TestStrings is preceded by a string terminator.

gdb/testsuite/ChangeLog:

	* gdb.base/examine-backward.c (Barrier): New character array
	constant, to ensure that TestStrings is preceded by a string
	terminator.
---
 gdb/testsuite/gdb.base/examine-backward.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/gdb/testsuite/gdb.base/examine-backward.c b/gdb/testsuite/gdb.base/examine-backward.c
index 5e9162a..ab04eff 100644
--- a/gdb/testsuite/gdb.base/examine-backward.c
+++ b/gdb/testsuite/gdb.base/examine-backward.c
@@ -32,6 +32,10 @@ literals.  The content of each array is the same as followings:
   };
 */
 
+const char Barrier[] = {
+  0x00,
+};
+
 const char TestStrings[] = {
   0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
   0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50,
-- 
2.5.0