ARC: Use new definitions for optional ARC CPU features

ARC: Use new definitions for optional ARC CPU features

GCC for ARC has been updated to provide consistent naming of preprocessor
definitions for different optional architecture features:

    * __ARC_BARREL_SHIFTER__ instead of __Xbarrel_shifter for
      -mbarrel-shifter
    * __ARC_LL64__ instead of __LL64__ for -mll64
    * __ARCEM__ instead of __EM__ for -mcpu=arcem
    * __ARCHS__ instead of __HS__ for -mcpu=archs
    * etc (not used in newlib)

This patch updates assembly routines for ARC to use new definitions instead
of a deprecated ones. To ensure compatibility with older compiler new
definitions are also defined in asm.h if needed, based on deprecated
preprocessor definitions.

*** newlib/ChangeLog ***
2015-12-15  Anton Kolesov  <Anton.Kolesov@synopsys.com>

	* libc/machine/arc/asm.h: Define new GCC definition for old compiler.
	* libc/machine/arc/memcmp-bs-norm.S: Use new GCC defines to detect
	  processor features.
	* libc/machine/arc/memcmp.S: Likewise.
	* libc/machine/arc/memcpy-archs.S: Likewise.
	* libc/machine/arc/memcpy-bs.S: Likewise.
	* libc/machine/arc/memcpy.S: Likewise.
	* libc/machine/arc/memset-archs.S: Likewise.
	* libc/machine/arc/memset-bs.S: Likewise.
	* libc/machine/arc/memset.S: Likewise.
	* libc/machine/arc/setjmp.S: Likewise.
	* libc/machine/arc/strchr-bs-norm.S: Likewise.
	* libc/machine/arc/strchr-bs.S: Likewise.
	* libc/machine/arc/strchr.S: Likewise.
	* libc/machine/arc/strcmp-archs.S: Likewise.
	* libc/machine/arc/strcmp.S: Likewise.
	* libc/machine/arc/strcpy-bs-arc600.S: Likewise.
	* libc/machine/arc/strcpy-bs.S: Likewise.
	* libc/machine/arc/strcpy.S: Likewise.
	* libc/machine/arc/strlen-bs-norm.S: Likewise.
	* libc/machine/arc/strlen-bs.S: Likewise.
	* libc/machine/arc/strlen.S: Likewise.
	* libc/machine/arc/strncpy-bs.S: Likewise.
	* libc/machine/arc/strncpy.S: Likewise.

Signed-off-by: Anton Kolesov <Anton.Kolesov@synopsys.com>