Require alloca for c-c++-common/Wstringop-truncation.c

2017-11-14  Tom de Vries  <tom@codesourcery.com>

	* c-c++-common/Wstringop-truncation.c: Require effective target alloca.

From-SVN: r254722

gcc/testsuite/ChangeLog

+2017-11-14  Tom de Vries  <tom@codesourcery.com>
+
+	* c-c++-common/Wstringop-truncation.c: Require effective target alloca.
+
 2017-11-13  Jan Hubicka  <hubicka@ucw.cz>
 
 	* gcc.dg/tree-ssa/fnsplit-2.c: New testcase.

gcc/testsuite/c-c++-common/Wstringop-truncation.c

 /* PR middle-end/81117 - Improve buffer overflow checking in strncpy
    { dg-do compile }
-   { dg-options "-O2 -Wstringop-truncation -Wno-stringop-overflow -ftrack-macro-expansion=0" } */
+   { dg-options "-O2 -Wstringop-truncation -Wno-stringop-overflow -ftrack-macro-expansion=0" }
+   { dg-require-effective-target alloca } */
 
 
 typedef __SIZE_TYPE__ size_t;