* configure, config.in: Rebuilt.

	* configure, config.in: Rebuilt.
	* configure.in: Check for realpath.
	* defs.h (gdb_realpath): Declare.
	* symtab.h (partial_symtab): Added fullname field.
	* source.c (openp): Use gdb_realpath.
	(forget_cached_source_info): Clear full name of each partial
	symtab.
	* utils.c (gdb_realpath): New function.
	* symtab.c (lookup_symtab): Removed.
	(lookup_symtab_1): Renamed to lookup_symtab.
	(lookup_symtab): Look for real path.
	(lookup_partial_symtab): Likewise.