* optabs.c (can_extend_p) Check HAVE_ptr_extend for a specialized
	pointer extension instruction.
	* combine.c (nonzero_bits,num_sign_bit_copies) Likewise.
	* simplify-rtx.c (simplify_unary_operation) Likewise.
	* explow.c (convert_memory_address) Check value of
	POINTERS_EXTEND_UNSIGNED to avoid some conversions when
	less than zero.
	* config/ia64/t-hpux (LIBGCC, INSTALL_LIBGCC, MULTILIB_OPTIONS,
	MULTILIB_DIRNAMES, MULTILIB_MATCHES) Add multilib support.
	* config/ia64/hpux.h (CPP_SPEC, ASM_SPEC, SUBTARGET_SWITCHES)
	Add Multilib Support.
	(POINTERS_EXTEND_UNSIGNED)  Define for ILP32 support.
	* config/ia64/ia64.h (MASK_ILP32, TARGET_ILP32, SUBTARGET_SWITCHES)
	Add Multilib Support.
	(POINTER_SIZE, LONG_TYPE_SIZE, MAX_LONG_TYPE_SIZE) Modify for ILP32
	support.
	* config/ia64/ia64.c (rtx_needs_barrier) Add support for addp4.
	* config/ia64/ia64.md (ptr_extend) New instruction to "swizzle"
	a 32 bit HP-UX pointer into a 64 bit HP-UX pointer.

From-SVN: r44166