[Patch] Teach genrecog/genoutput that scratch registers require write constraint modifiers
gcc/
* doc/md.texi (Modifiers): Consistently use "read/write"
nomenclature rather than "input/output".
* genrecog.c (constraints_supported_in_insn_p): New.
(validate_pattern): If needed, also check constraints on
MATCH_SCRATCH operands.
* genoutput.c (validate_insn_alternatives): Catch earlyclobber
operands with no '=' or '+' modifier.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@215388 138bc75d-0d04-0410-961f-82ee72b054a4