[PR99123] inline-asm: Don't use decompose_mem_address to find used hard regs

[PR99123] inline-asm: Don't use decompose_mem_address to find used hard regs

Inline asm in question has empty constraint which means anything
including memory with invalid address.  To check used hard regs we
used decompose_mem_address which assumes memory with valid address.
The patch implements the same semantics without assuming valid
addresses.

gcc/ChangeLog:

	PR inline-asm/99123
	* lra-constraints.c (uses_hard_regs_p): Don't use decompose_mem_address.

gcc/testsuite/ChangeLog:

	PR inline-asm/99123
	* gcc.target/i386/pr99123.c: New.