* coretypes.h (const_bitmap, const_rtx, const_rtvec, const_tree):
	New.
	
	* rtl.h (RTL_CHECK1, RTL_CHECK2, RTL_CHECKC1, RTL_CHECKC2,
	RTVEC_ELT, XWINT, XCWINT, XCMWINT, XCNMPRV, BLOCK_SYMBOL_CHECK,
	RTL_FLAG_CHECK1, RTL_FLAG_CHECK2, RTL_FLAG_CHECK3,
	RTL_FLAG_CHECK4, RTL_FLAG_CHECK5, RTL_FLAG_CHECK6,
	RTL_FLAG_CHECK7, RTL_FLAG_CHECK8, LABEL_KIND, SET_LABEL_KIND):
	Preserve const-ness of parameters through use of __typeof(),
	also constify and tidy.
	
	* tree.h (TREE_CHECK, TREE_NOT_CHECK, TREE_CHECK2,
	TREE_NOT_CHECK2, TREE_CHECK3, TREE_NOT_CHECK3, TREE_CHECK4,
	NON_TREE_CHECK4, TREE_CHECK5, TREE_NOT_CHECK5,
	CONTAINS_STRUCT_CHECK, TREE_CLASS_CHECK, TREE_RANGE_CHECK,
	OMP_CLAUSE_SUBCODE_CHECK, OMP_CLAUSE_RANGE_CHECK, EXPR_CHECK,
	GIMPLE_STMT_CHECK, NON_TYPE_CHECK, TREE_VEC_ELT_CHECK,
	PHI_NODE_ELT_CHECK, OMP_CLAUSE_ELT_CHECK, TREE_OPERAND_CHECK,
	TREE_OPERAND_CHECK_CODE, GIMPLE_STMT_OPERAND_CHECK,
	TREE_RTL_OPERAND_CHECK, TREE_CHAIN, TREE_TYPE): Likewise.

From-SVN: r126918