homogenise the repr of generics / dyn Trait / (*mut/*const/&/&mut) dyn Trait

hmg.txt

homogenise the repr of generics / dyn Trait / (*mut/*const/&/&mut) dyn Trait
 
abstract value = (generic / dyn Trait / (*mut/*const/&/&mut) dyn Trait) value;
abstracted function = (takes at least one arg that is abstract or returns abstract value) and the fun is nonspecialisible;
at the 'lower level' abstract args are represented by wide pointers;
devise some opt passes to 'degeneralise' uses of abstracted funs at some sites;
specifically: 
1. uses within an 'inner world' (libs with visible impl)
2. cross bondry code must be generated to adhere to the wide pointer repr tho

syntax has to be changed to make abstracted fun pointers expressible at surface level
fn_ptr as fn <T>(T) -> T where T: Debug should be valid syntax

by default abstracted funs are noninlineable unless
1. marked #[inline]
2. called with inline_call!() macro
	let _ = inline_call!(abstracted_fun_ident(...)); // ok
	let _ = inline_call!(fn_ptr as fn <T>(T) -> T where ...); // compile time error


Two cases of ret vals
1. fn <...>(...) -> Sized -- actually not a problem at all!
2. fn <...>(...) -> Unsized -- unknown retval size in general case
	(u32,u32)[u8;?]
	size	 ^
	  align	 fn_ptr points here

	funs returning dynsized retvals are invokable only through indirect_call!() macro
	let layout = unsized_fun_retval_layout!(unsized_fun_ptr); // ask how much space is needed for return value
	let mut retval_storage_ptr = ...;
	let () = indirect_call!(abstracted_fun_ptr, (args...), &raw mut retval_storage_ptr);
		
		
rdylib2 format
	1. os/cpu-arch dependent output!
	2. should contain ty mtd by default (alt: making type binding unsafe is undesirable)
	3. lang builtins to query symbols in the rdylib2 ?
		try_get_sym_by_name(lib_start_addr:*mut (), name:&'static str) -> Option<OpaqueSymRef>
		try_bind_type<T>(sym_ref:OpaqueSymRef) -> Option<SymRef<T>>
		try_bind_type_unchecked<T>(sym_ref:OpaqueSymRef) -> SymRef<T>
	[lib_mtd]
	magic_num (4bytes 'rdl2')
	lib_name (len:u16, chars:[u8;len])
	lib_format (v1 = name_hash:u64, ty_hash:u64, code_section_offset:u64)
	[sym_tab]
	(name_hash)
	...
	(ty_hash, code_section_offset)
	...
	[code]
	...