Fix libsanitizer build with old kernel headers on ARM after r230739.

libsanitizer/

	* include/system/linux/asm/ptrace.h: New header.

From-SVN: r230790

libsanitizer/ChangeLog

+2015-11-24  Maxim Ostapenko  <m.ostapenko@partner.samsung.com>
+
+	* include/system/linux/asm/ptrace.h: New header.
+
 2015-11-23  Maxim Ostapenko  <m.ostapenko@partner.samsung.com>
 
 	* All source files: Merge from upstream r253555.

libsanitizer/include/system/linux/asm/ptrace.h

+#include_next <linux/asm/ptrace.h>
+/* ARM_VFPREGS_SIZE has been added in 3.0 */
+#if defined(__arm__) && !defined(ARM_VFPREGS_SIZE)
+/* The size of the user-visible VFP state as seen by PTRACE_GET/SETVFPREGS
+   and core dumps.  */
+#define ARM_VFPREGS_SIZE ( 32 * 8 /*fpregs*/ + 4 /*fpscr*/ )
+#endif