[PR99422] LRA: Skip modifiers when processing memory address.

[PR99422] LRA: Skip modifiers when processing memory address.

  Function process_address_1 can wrongly look at constraint modifiers
instead of the 1st constraint itself.  The patch solves the problem.

gcc/ChangeLog:

	PR target/99422
	* lra-constraints.c (skip_contraint_modifiers): New function.
	(process_address_1): Use it before lookup_constraint call.