elf symbol size

elf symbol size

This changes elf_obj_sy.size from being malloc'd to being on the notes
obstack.  That means no code needs to free these expressions, which in
turn means that the size expression can be shared when cloning
symbols.  Nothing modifies the size expressions except when resolving.
In all cases I could see, if the size changes the entire expression is
replaced.

The patch also extracts code from elf_copy_symbol_attributes into a
separate function for use by riscv and aarch64.

	* config/obj-elf.c (elf_obj_symbol_clone_hook): Delete.
	(elf_copy_symbol_size): New function, extracted and modified from..
	(elf_copy_symbol_attributes): ..here.
	(obj_elf_size): Don't free size and use notes_alloc.
	(elf_frob_symbol): Don't free size.
	(elf_format_ops): Zero symbol_clone_hook.
	* config/obj-elf.h (elf_obj_symbol_clone_hook): Delete.
	(obj_symbol_clone_hook): Don't define.
	(elf_copy_symbol_size): Declare.
	* config/tc-aarch64.c (aarch64_elf_copy_symbol_attributes): Delete.
	* config/tc-aarch64.h (OBJ_COPY_SYMBOL_ATTRIBUTES): Define as
	elf_copy_symbol_size.
	* config/tc-alpha.c (s_alpha_end): notes_alloc symbol size exp.
	* config/tc-ia64.c (dot_endp): Likewise.
	* config/tc-kvx.c (kvx_endp): Likewise.
	* config/tc-mips.c (s_mips_end): Likewise.
	* config/tc-riscv.c (riscv_elf_copy_symbol_attributes): Delete.
	* config/tc-riscv.h (OBJ_COPY_SYMBOL_ATTRIBUTES): Define as
	elf_copy_symbol_size.