i386: Fix build by GCC 5.0

Fixed 3 "make check" failures on glibc 32bit built by gcc 5.0 due to EBX
was enabled for allocation:

https://gcc.gnu.org/ml/gcc-patches/2014-10/msg00892.html

Tests elf/tst-tls3, elf/tst-execstack-needed, elf/tst-execstack-prog
were failed because EBX was used as PIC register.

	* sysdeps/i386/tls-macros.h: Include <features.h>.
	(TLS_LE): Use non-PIC version for GCC >= 5.0.
	(TLS_IE): Likewise.
	(TLS_LD): Likewise.
	(TLS_GD): Likewise.
	* sysdeps/unix/sysv/linux/i386/sysdep.h (check_consistency): Don't
	define for GCC >= 5.0.

ChangeLog

@@ -1,3 +1,13 @@
+2014-12-30  Andrew Senkevich  <andrew.senkevich@intel.com>
+
+	* sysdeps/i386/tls-macros.h: Include <features.h>.
+	(TLS_LE): Use non-PIC version for GCC >= 5.0.
+	(TLS_IE): Likewise.
+	(TLS_LD): Likewise.
+	(TLS_GD): Likewise.
+	* sysdeps/unix/sysv/linux/i386/sysdep.h (check_consistency): Don't
+	define for GCC >= 5.0.
+
 2014-12-30  Chris Metcalf  <cmetcalf@ezchip.com>
 
 	* math/test-fenv.c (test_single_exception, set_single_exc,

sysdeps/i386/tls-macros.h

@@ -1,11 +1,13 @@
+#include <features.h> /* For __GNUC_PREREQ.  */
+
 #define TLS_LE(x) \
   ({ int *__l;								      \
      asm ("movl %%gs:0,%0\n\t"						      \
 	  "subl $" #x "@tpoff,%0"					      \
 	  : "=r" (__l));						      \
      __l; })
 
-#ifdef PIC
+#if defined PIC && !__GNUC_PREREQ (5,0)
 # define TLS_IE(x) \
   ({ int *__l;								      \
      asm ("movl %%gs:0,%0\n\t"						      \
@@ -27,7 +29,7 @@
      __l; })
 #endif
 
-#ifdef PIC
+#if defined PIC && !__GNUC_PREREQ (5,0)
 # define TLS_LD(x) \
   ({ int *__l, __c, __d;						      \
      asm ("leal " #x "@tlsldm(%%ebx),%%eax\n\t"				      \
@@ -51,7 +53,7 @@
      __l; })
 #endif
 
-#ifdef PIC
+#if defined PIC && !__GNUC_PREREQ (5,0)
 # define TLS_GD(x) \
   ({ int *__l, __c, __d;						      \
      asm ("leal " #x "@tlsgd(%%ebx),%%eax\n\t"				      \

sysdeps/unix/sysv/linux/i386/sysdep.h

@@ -502,7 +502,7 @@ asm (".L__X'%ebx = 1\n\t"
 #endif
 
 /* Consistency check for position-independent code.  */
-#ifdef __PIC__
+#if defined __PIC__ && !__GNUC_PREREQ (5,0)
 # define check_consistency()						      \
   ({ int __res;								      \
      __asm__ __volatile__						      \