Defined but unused target macros

[Joseph S. Myers]

There are a lot of target macros that are defined (possibly commented out)  
but never used anywhere.  Most of them are also undocumented.  Here is a
partial list; I've removed many that appear target-specific, supposing
that e.g. a target maintainer may want a target-specific predicate to be
there even if there are no current users.

Please let me know if:

* Any of these are actually used in the compiler at present.
* Any of these are used in patches you've submitted to the rest of the 
compiler, and are present in your target pending review of those patches.
* Any of these are defined in your target and you want them to remain,
notwithstanding that they are currently unused.

Otherwise I'll probably submit a patch to remove them.  Of course feel
free to remove unused macros from your own target, and to state if you
know that any particular macros here definitely are obsolete and should be
removed.

ADJUST_COST
ALWAYS_PUSH_CONSTS_USING_REGS_P
ASM_COMMENT_END
ASM_DOUBLE
ASM_FLOAT
ASM_GLOBAL
ASM_IDENTIFY_GCC
ASM_INT_OP
ASM_LONGDOUBLE
ASM_OPERAND_LETTER
ASM_OUTPUT_ASM
ASM_OUTPUT_INTERNAL_LABELREF
ASM_OUTPUT_XDATA_CHAR
ASM_OUTPUT_XDATA_DOUBLE_INT
ASM_OUTPUT_XDATA_INT
ASM_OUTPUT_XDATA_SHORT
ASM_PROG
BASE_PASSING_ARG_REG
BITS_PER_HIGH
BITS_PER_LO_SUM
BLOCK_PROFILER_LENGTH
BLOCK_PROFILING_CODE
BRANCH_LIKELY_P
BYTE_LOADS_ZERO_EXTEND
CASE_TAKES_INDEX_RAW
CC1_CPU_DEFAULT_SPEC
COMPARE_FLAG_MODE
CONSTRUCTOR_NAME_FORMAT
CROSS_ASM_SPEC
CROSS_LINK_SPEC
CRT0_DUMMIES
DBX_NO_EXTRA_TAGS
DEC_OSF1
DEFAULT_ASSEMBLER_DIALECT
DEFAULT_HARD_FP_REGNUM
DONT_ACCESS_GBLS_AFTER_EPILOGUE
DOUBLE_ASM_OP
EASY_DIV_EXPR
ENABLE_REGMOVE_PASS
EXPAND_BUILTIN_NEXT_ARG
EXTRA_FORMAT_FUNCTIONS
FASCIST_ASSEMBLER
FIX_FRAME_POINTER_ADDRESS
FLOATUNSSITF2_LIBCALL
FLOAT_ASM_OP
FORCE_EH_FRAME_INFO_IN_DATA_SECTION
FUNCTION_BLOCK_PROFILER_LENGTH
FUNCTION_INCOMING_ARG_REGNO_P
FUNCTION_VALUEX
GEN_BINDER_NAME_FOR_STUB
GIV_SORT_CRITERION
GROUP_BITFIELDS_BY_ALIGN
HARD_AP_REGNUM
HAVE_ATEXIT
HOST_PTR_AS_INT
IDENT_DIRECTIVE
IMPLICIT_FIX_EXPR
INCOMING_REGNO_P
INDEXABLE_ADDRESS_P
INTEGER_CLASS_P
LD_PROG
LEGITIMATE_DISPLACEMENT_P
LIBG_SPEC
LITERAL_COMPARE_BETTER_UNSIGNED
LONGJMP_RESTORE_FROM_STACK
LONG_FP_REGS_P
LOOP_TEST_THRESHOLD
MAX_PARM_BOUNDARY
NON_COMMUTATIVE_CODE_P
NON_STACK_REG_P
NO_LIB_PROTOTYPE
OBJ_ELF
OBJ_SOM
PACK_INSNS
PCC_BITFIELDS_TYPE_MATTERS
PCC_BITFIELD_TYPE_TEST
PROMOTE_RETURN
PUT_SDB_DIM
REGISTER_PREFIX_MD
RETURN_ADDR_OFF
REWRITE_ADDRESS
RODATA_SECTION_ASM_OP
SLOW_SHORT_ACCESS
STDC_VALUE
SVR3_target
TRAMPOLINE_ALIGN
UNIQUE_SECTION_P
USE_BIN_AS
USE_BIN_LD
USE_COLLECT
USE_GNU_LD
USE_LIBG
USING_AOUTOS_H
USING_CONFIG_FREEBSD
USING_CONFIG_FREEBSD_SPEC
USING_PSOS_H
WARN_FOUR_CHAR_CONSTANTS
WEAK_ASM_OP
WIN32_UWIN_TARGET
WINT_TYPE_SIZE
WORD_SWITCH
XEXP_
_ASM_OUTPUT_LONG

-- 
Joseph S. Myers
jsm28@cam.ac.uk