x86: Add {noimm8s} pseudo prefix

x86: Add {noimm8s} pseudo prefix

Instruction templates with only sign-extended 8-bit immediate operand
also have a second template with full-operand-size immediate operand
under a different opcode.  Add {noimm8s} pseudo prefix to exclude
templates with only sign-extended 8-bit immediate operand.

gas/

	PR gas/32811
	* config/tc-i386.c (pseudo_prefixes): Add no_imm8s.
	(operand_size_match): Return false for templates with only sign-
	extended 8-bit immediate operand if {noimm8s} is used.
	(parse_insn): Handle Prefix_NoImm8s.
	* doc/c-i386.texi: Document {noimm8s}.
	* testsuite/gas/i386/pseudos.s: Add tests for {noimm8s}.
	* testsuite/gas/i386/x86-64-pseudos.s: Likewise.
	* testsuite/gas/i386/pseudos.d: Updated.
	* testsuite/gas/i386/x86-64-pseudos.d: Likewise.

opcodes/

	PR gas/32811
	* opcodes/i386-opc.h (Prefix_NoImm8s): New.
	* i386-opc.tbl: Add {noimm8s} pseudo prefix.
	* i386-mnem.h: Regenerated.
	* i386-tbl.h: Likewise.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>