* ada-lang.c: Update throughout to use symbol_matches_domain

	* ada-lang.c: Update throughout to use symbol_matches_domain
	instead of matching the symbol domain explictly.
	* dwarf2read.c (add_partial_symbol): Do not add new psym for
	STRUCT_DOMAIN. Make sure you recognize c++ struct and java and ada
	class as typedefs. See lookup_partial_symbol function.
	(new_symbol): Similar to add_partial_symbol, do not create
	symbol for the typedef. See lookup_block_symbol.
	* symtab.c (symbol_matches_domain): New function, takes care
	of dual meaning of STRUCT_DOMAIN symbol for c++, ada and java.
	(lookup_partial_symbol): Use symbol_matches_domain to see if the
	found psym domain matches the given domain.
	(lookup_block_symbol): Likewise.