re PR target/65261 (bootstrap-ubsan ppc64le: gcc/libcpp/lex.c:552:30: runtime error...

re PR target/65261 (bootstrap-ubsan ppc64le: gcc/libcpp/lex.c:552:30: runtime error: load of misaligned address 0x01002172dfc6 for type 'const uchar', which requires 16 byte alignment)

Fix PR65261

Running bootstrap-ubsan on ppc64le shows many instances of:

  libcpp/lex.c:552:30: runtime error: load of misaligned address
  0x01001f31d37a for type 'const uchar', which requires 16 byte alignment

But the unaligned vector loads are intended in this case, because they
are preferable to forced-alignment on POWER8. So just silence the ubsan
errors.

2015-03-02  Markus Trippelsdorf  <markus@trippelsdorf.de>

include/
	PR target/65261
	* ansidecl.h (ATTRIBUTE_NO_SANITIZE_UNDEFINED): New macro.

libcpp/
	PR target/65261
	* lex.c (search_line_fast): Silence ubsan errors.

From-SVN: r221190