X86: Allow additional ISAs for IAMCU in assembler
    
    Originally only Pentium integer instructions are allowed for IAMCU.
    This patch removes such a restriction.  For example, 387 and SSE2
    instructions can be enabled by passing "-march=iamcu+sse2+387" to
    assembler.
    
    gas/
    
    	* config/tc-i386.c (valid_iamcu_cpu_flags): Removed.
    	(set_cpu_arch): Updated.
    	(md_parse_option): Likewise.
    	* testsuite/gas/i386/i386.exp: Run iamcu-4 and iamcu-5.  Remove
    	iamcu-inval-2 and iamcu-inval-3.
    	* testsuite/gas/i386/iamcu-4.d: New file.
    	* testsuite/gas/i386/iamcu-4.s: Likewise.
    	* testsuite/gas/i386/iamcu-5.d: Likewise.
    	* testsuite/gas/i386/iamcu-5.s: Likewise.
    	* testsuite/gas/i386/iamcu-inval-2.l: Removed.
    	* testsuite/gas/i386/iamcu-inval-2.s: Likewise.
    	* testsuite/gas/i386/iamcu-inval-3.l: Likewise.
    	* testsuite/gas/i386/iamcu-inval-3.s: Likewise.
    
    opcodes/
    
    	* i386-gen.c (cpu_flag_init): Remove CPU_IAMCU_COMPAT_FLAGS.
    	* i386-init.h: Regenerated.