lra_insn_reg and lra_operand_data have both a bitmask of earlyclobber
alternatives and an overall boolean.  The danger is that we then test
the overall boolean when really we should be testing for a particular
alternative.  This patch gets rid of the boolean and tests the mask
against zero when we really do need to test "any alternative might
be earlyclobber".  (I think the only instance of that is the
LRA_UNKNOWN_ALT handling in lra-lives.c:reg_early_clobber_p.)

This is needed (and tested) by an upcoming SVE patch.

2019-07-31  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* lra-int.h (lra_operand_data): Remove early_clobber field.
	(lra_insn_reg): Likewise.
	* lra.c (debug_operand_data): Update accordingly.
	(setup_operand_alternative): Likewise.
	(new_insn_reg): Likewise.  Remove early_clobber parameter.
	(collect_non_operand_hard_regs): Update call accordingly.
	Don't assign to lra_insn_reg::early_clobber.
	(add_regs_to_insn_regno_info): Remove early_clobber parameter
	and update calls to new_insn_reg.
	(lra_update_insn_regno_info): Update calls accordingly.
	* lra-constraints.c (update_and_check_small_class_inputs): Take the
	alternative number as a parameter and test whether the operand
	is earlyclobbered in that particular alternative.
	(process_alt_operands): Update call accordingly.  Use per-alternative
	checks for earyclobber here too.
	* lra-lives.c (reg_early_clobber_p): Check early_clobber_alts
	against zero for IRA_UNKNOWN_ALT.

From-SVN: r273921