When lra-remat rematerializes an instruction with a clobber, it checks that the clobber does not kill live registers.

When lra-remat rematerializes an instruction with a clobber, it checks
that the clobber does not kill live registers.  However it fails to check
that the clobber also doesn't overlap with the destination register of the
final rematerialized instruction.  As a result it is possible to generate
illegal instructions with the same hard register as the destination and a
clobber.  Fix this by also checking for overlaps with the destination
register.

    gcc/
	PR rtl-optimization/80754
	* lra-remat.c (do_remat): Add overlap checks for dst_regno.

From-SVN: r248424