* flag-types.h (enum sanitize_code): Add SANITIZE_SHIFT_BASE
	and SANITIZE_SHIFT_EXPONENT, change SANITIZE_SHIFT to bitwise
	or of them, renumber other enumerators.
	* opts.c (sanitizer_opts): Add shift-base and shift-exponent.
	* doc/invoke.texi: Document -fsanitize=shift-base and
	-fsanitize-shift-exponent, document -fsanitize=shift as
	having those 2 suboptions.
c-family/
	* c-ubsan.c (ubsan_instrument_shift): Handle split
	-fsanitize=shift-base and -fsanitize=shift-exponent.
testsuite/
	* gcc.dg/ubsan/c99-shift-3.c: New test.
	* gcc.dg/ubsan/c99-shift-4.c: New test.
	* gcc.dg/ubsan/c99-shift-5.c: New test.
	* gcc.dg/ubsan/c99-shift-6.c: New test.

From-SVN: r242005