x86: Remove support for old (<= 2.8.1) versions of gcc

x86: Remove support for old (<= 2.8.1) versions of gcc

Old (<= 2.8.1) versions of gcc generate broken fsubp, fsubrp, fdivp and
fdivrp instructions.  Assembler translates them to correct ones with a
warning:

[hjl@gnu-cfl-1 gas]$ cat x.s
	fsubp %st(3),%st
[hjl@gnu-cfl-1 gas]$ gcc -c x.s
x.s: Assembler messages:
x.s:1: Warning: translating to `fsubp %st,%st(3)'
[hjl@gnu-cfl-1 gas]$

This patch removes support for old (<= 2.8.1) versions of gcc:

[hjl@gnu-cfl-1 gas]$ ./as-new -o x.o x.s
x.s: Assembler messages:
x.s:1: Error: operand type mismatch for `fsubp'
[hjl@gnu-cfl-1 gas]$

gas/

	* NEWS: Mention -mold-gcc removal.
	* config/tc-i386.c (i386_error): Remove old_gcc_only.
	(old_gcc): Removed.
	(match_template): Remove old gcc support.
	(OPTION_MOLD_GCC): Removed.
	(OPTION_MRELAX_RELOCATIONS): Updated.
	(md_longopts): Remove OPTION_MOLD_GCC.
	(md_parse_option): Likewise.
	(md_show_usage): Remove -mold-gcc.
	* testsuite/gas/i386/general.s: Convert fsub/fdiv tests for old
	(<= 2.8.1) versions of gcc.
	* testsuite/gas/i386/intel.s: Likewise.
	* testsuite/gas/i386/general.l: Updated.
	* testsuite/gas/i386/intel-intel.d: Likewise.
	* testsuite/gas/i386/intel.d: Likewise.
	* testsuite/gas/i386/intel.e: Likewise.
	* testsuite/gas/i386/i386.exp: Don't pass -mold-gcc to general.

include/

	* opcode/i386 (OLDGCC_COMPAT): Removed.

opcodes/

	* i386-gen.c (opcode_modifiers): Remove OldGcc.
	* i386-opc.h (OldGcc): Removed.
	(i386_opcode_modifier): Remove oldgcc.
	* i386-opc.tbl: Remove fsubp, fsubrp, fdivp and fdivrp
	instructions for old (<= 2.8.1) versions of gcc.
	* i386-tbl.h: Regenerated.