Fix builtins/*-chk.c testcases for -fuse-linker-plugin

[Jan Hubicka]

Hi,
these testcases are optimized little too much, so some *_chk calls are optimized
away that should not be.  The use of externally visible vars is not good enough
since we bring them static and constant propagate.

regtested x86_64-linux, OK?
Honza

	* snprintf-chk.c (ptr): Declare volatile.
	* strcpy-chk.c (s2, s3, l1): Declare volatile.
	* snprintf-chk.c (ptr): Declare volatile.
	* vsprintf-chk.c (ptr): Declare volatile.
	* vsnprintf-chk.c (ptr): Declare volatile.
Index: snprintf-chk.c
===================================================================
*** snprintf-chk.c	(revision 167242)
--- snprintf-chk.c	(working copy)
*************** char *s3 = "FGH";
*** 21,27 ****
  char *s4;
  size_t l1 = 1;
  static char buffer[32];
! char *ptr = "barf";
  
  void
  __attribute__((noinline))
--- 21,27 ----
  char *s4;
  size_t l1 = 1;
  static char buffer[32];
! char * volatile ptr = "barf";
  
  void
  __attribute__((noinline))
Index: strncpy-chk.c
===================================================================
*** strncpy-chk.c	(revision 167242)
--- strncpy-chk.c	(working copy)
*************** extern void *memset (void *, int, size_t
*** 16,25 ****
  
  const char s1[] = "123";
  char p[32] = "";
! char *s2 = "defg";
! char *s3 = "FGH";
  char *s4;
! size_t l1 = 1;
  int i;
  
  void
--- 16,25 ----
  
  const char s1[] = "123";
  char p[32] = "";
! char * volatile s2 = "defg";
! char * volatile s3 = "FGH";
  char *s4;
! volatile size_t l1 = 1;
  int i;
  
  void
Index: sprintf-chk.c
===================================================================
*** sprintf-chk.c	(revision 167242)
--- sprintf-chk.c	(working copy)
*************** char *s3 = "FGH";
*** 20,26 ****
  char *s4;
  size_t l1 = 1;
  static char buffer[32];
! char *ptr = "barf";
  
  void
  __attribute__((noinline))
--- 20,26 ----
  char *s4;
  size_t l1 = 1;
  static char buffer[32];
! char * volatile ptr = "barf";
  
  void
  __attribute__((noinline))
Index: vsprintf-chk.c
===================================================================
*** vsprintf-chk.c	(revision 167242)
--- vsprintf-chk.c	(working copy)
*************** char *s3 = "FGH";
*** 22,28 ****
  char *s4;
  size_t l1 = 1;
  static char buffer[32];
! char *ptr = "barf";
  
  int
  __attribute__((noinline))
--- 22,28 ----
  char *s4;
  size_t l1 = 1;
  static char buffer[32];
! char * volatile ptr = "barf";
  
  int
  __attribute__((noinline))
Index: vsnprintf-chk.c
===================================================================
*** vsnprintf-chk.c	(revision 167242)
--- vsnprintf-chk.c	(working copy)
*************** char *s3 = "FGH";
*** 22,28 ****
  char *s4;
  size_t l1 = 1;
  static char buffer[32];
! char *ptr = "barf";
  
  int
  __attribute__((noinline))
--- 22,28 ----
  char *s4;
  size_t l1 = 1;
  static char buffer[32];
! char * volatile ptr = "barf";
  
  int
  __attribute__((noinline))