* lib/jit_x86-cpu.c, lib/jit_x86-sse.c, lib/jit_x86-x87.c:
	Correct encoding of ldxr* stxr* in the x32 abi. If the
	displacement register is negative, it would generate
	a 64 bit instruction with a 32 bit unsigned displacement.

	* check/ranger.tst, check/ranger.ok: New files, implementing
	a test case for negative loads and stores. This is range.tst
	converted to use registers instead of immediate offsets.

	check/Makefile.am: Update for the new test case.