i386: Fix up z operand modifier diagnostics on inline-asm [PR109458]

i386: Fix up z operand modifier diagnostics on inline-asm [PR109458]

On the following testcase, we emit weird diagnostics.
User used the z modifier, but diagnostics talks about Z instead.
This is because z is implemented by doing some stuff and then falling
through into the Z case.

The following patch adjusts the Z diagnostics, such that it prints whatever
modifier user actually uses in places which could happen with either
modifier.

Furthermore, in case of the non-integer operand used with operand code %<z%>
warning the warning location was incorrect (and of function), so I've used
warning_for_asm to get it a proper location in case it is a user inline-asm.

2023-04-12  Jakub Jelinek  <jakub@redhat.com>

	PR target/109458
	* config/i386/i386.cc: Include rtl-error.h.
	(ix86_print_operand): For z modifier warning, use warning_for_asm
	if this_is_asm_operands.  For Z modifier errors, use %c and code
	instead of hardcoded Z.

	* gcc.target/i386/pr109458.c: New test.