(CPP_SPEC): Add defines for the cpu type, hard or soft floating point, and the APCS PC size.

(CPP_SPEC): Add defines for the cpu type, hard or soft floating
point, and the APCS PC size.
(TARGET_*): Restructure.
(ARM_FLAG_*): Many new definitions for different target options, not
all of which are supported yet.
(TARGET_SWITCHES): Use the ARM_FLAG_* definitions instead of explicit
numbers.
(prog_mode_type): New enum.
(floating_point_type): Split emulated floating point into FP_SOFT[23].
(OVERRIDE_OPTIONS): Call arm_override_options.
	(ARM_CPU_NAME): Default to NULL if not defined by a subtarget.
(BYTES_BIG_ENDIAN): Can now be set as a compilation option.
(RETURN_IN_MEMORY, DEFAULT_PCC_STRUCT_RETURN): New definitions.
(GO_IF_LEGITIMATE_OFFSET): Use different HImode offsets if compiling
for an architecture 4 target.  The offsets for floating point
constants are the same as for integers if compiling TARGET_SOFT_FLOAT
(GO_IF_LEGITIMATE_ADDRESS): Don't allow PRE_INC and POST_DEC if
the size is more than 4 bytes.  Restrict the range offsets for DImode;
likewise for DFmode when TARGET_SOFT_FLOAT.
(LEGITIMIZE_ADDRESS): Use symbol_mentioned_p, not LEGITIMATE_CONSTANT_P
to determine if a constant address might be better in a register.
Handle DFmode addresses in the same way as DImode if TARGET_SOFT_FLOAT.
(LOAD_EXTEND_OP): If arm_arch4, then HImode also zero-extends.
(SECONDARY_OUTPUT_RELOAD_CLASS): No need to handle floating
point constants any more, since arm_reorg will deal with them.
(LEGITIMATE_CONSTANT_P): Is now anything that doesn't contain a
LABEL.
(GO_IF_LEGITIMATE_ADDRESS): Recognize addresses expressions generated
by arm_reorg, but only after reload has completed.
(MACHINE_DEPENDENT_REORG): Define.
(ASM_OUTPUT_SPECIAL_POOL_ENTRY): There should be nothing left in
the pool, even if it might look like it.
(most assembler-specific defines): Move to arm/aout.h.
(CONSTANT_ADDRESS_P): Can't directly access constant strings when
	generating assembler for ARMASM.
(ENCODE_SECTION_INFO): Don't define if generating ARMASM assembler.
(ASM_OUTPUT_INTERNAL_LABEL): Generalize, so that it can be used
with all targeted assemblers.
(ASM_OUTPUT_LABEL): Call arm_asm_output_label.

From-SVN: r10681