General cleanup of feature definitions.

General cleanup of feature definitions.
* tc-arm.c (ARM_EXT_LONGMUL, ARM_EXT_HALFWORD, ARM_EXT_THUMB): Delete.
(ARM_2UP, ARM_ALL, ARM_3UP, ARM_6UP): Delete.
(FPU_CORE, FPU_FPA10, FPA_FPA11, FPU_ALL, FPA_MEMMULTI): Delete.
(ARM_EXT_V{1,2,2S,3,3M,4,4T,5T,5ExP}): New defines.
(ARM_EXT_V{5,5E}): Synchronize with above.
(ARM_ARCH_V*): Define a complete set in terms of above features.
(ARM_{1,2,3,250,6,7,8,9,STRONG}): Define in terms of architecture.
(FPU_FPA_EXT_V[12]): Define.
(FPU_ARCH_FPE, FPU_ARCH_FPA): Define in terms of above.
(FPU_ANY): Define.
(FPU_DEFAULT): Default to FPA.
(CPU_DEFAULT): For XScale, this is now just ARM_ARCH_XSCALE; for
Thumb, this is now ARM_ARCH_V5T.
(insns): Rework for new feature defines.
(tinsns): Likewise.
(opcode_select, do_ldst, md_begin, md_parse_option): Likewise.