x86: Add {disp16} pseudo prefix

x86: Add {disp16} pseudo prefix

Use Prefix_XXX for pseudo prefixes.  Add {disp16} pseudo prefix and
replace {disp32} pseudo prefix with {disp16} in 16-bit mode test.
Check invalid {disp16}/{disp32} pseudo prefixes.

gas/

	PR gas/26305
	* config/tc-i386.c (_i386_insn::disp_encoding): Add
	disp_encoding_16bit.
	(parse_insn): Check Prefix_XXX for pseudo prefixes.  Handle
	{disp16}.
	(build_modrm_byte): Handle {disp16}.
	(i386_index_check): Check invalid {disp16} and {disp32} pseudo
	prefixes.
	* doc/c-i386.texi: Update {disp32} documentation and document
	{disp16}.
	* testsuite/gas/i386/i386.exp: Run x86-64-inval-pseudo.
	* testsuite/gas/i386/inval-pseudo.s: Add {disp32}/{disp16}
	tests.
	* testsuite/gas/i386/pseudos.s: Add {disp8}/{disp32} vmovaps
	tests with 128-byte displacement.  Add {disp16} tests.
	* testsuite/gas/i386/x86-64-pseudos.s: Add {disp8}/{disp32}
	vmovaps test.  Add (%r13)/(%r13d) tests.
	* testsuite/gas/i386/x86-64-inval-pseudo.l: New file.
	* testsuite/gas/i386/x86-64-inval-pseudo.s: Likewise.
	* testsuite/gas/i386/inval-pseudo.l: Updated.
	* testsuite/gas/i386/pseudos.d: Likewise.
	* testsuite/gas/i386/x86-64-pseudos.d: Likewise.

opcodes/

	PR gas/26305
	* i386-opc.h (Prefix_Disp8): New.
	(Prefix_Disp16): Likewise.
	(Prefix_Disp32): Likewise.
	(Prefix_Load): Likewise.
	(Prefix_Store): Likewise.
	(Prefix_VEX): Likewise.
	(Prefix_VEX3): Likewise.
	(Prefix_EVEX): Likewise.
	(Prefix_REX): Likewise.
	(Prefix_NoOptimize): Likewise.
	* i386-opc.tbl: Use Prefix_XXX on pseudo prefixes.  Add {disp16}.
	* i386-tbl.h: Regenerated.