[PR118017][LRA]: Don't inherit reg of non-uniform reg class

[PR118017][LRA]: Don't inherit reg of non-uniform reg class

In the PR case LRA inherited value of register of class INT_SSE_REGS
which resulted in LRA cycling when LRA tried to use different move
alternatives with SSE/general regs and memory.  The patch rejects to
inherit such (non-uniform) classes to prevent cycling.

gcc/ChangeLog:

	PR target/118017
	* lra-constraints.cc (inherit_reload_reg): Check reg class on uniformity.

gcc/testsuite/ChangeLog:

	PR target/118017
	* gcc.target/i386/pr118017.c: New.