yet another attempt at auto-linking

store only the original import path string (+ .a)
if 6g resolves it to an archive file.
let 6l re-resolve the .a at link time.

this lets libraries build against an archive
in the current directory but get used
against an installed archive.

R=r
OCL=27244
CL=27244
diff --git a/src/cmd/gc/go.h b/src/cmd/gc/go.h
index b3f8a50b..256f624 100644
--- a/src/cmd/gc/go.h
+++ b/src/cmd/gc/go.h
@@ -703,7 +703,7 @@
 void	yyerror(char*, ...);
 void	warn(char*, ...);
 void	fatal(char*, ...);
-void	linehist(char*, int32);
+void	linehist(char*, int32, int);
 int32	setlineno(Node*);
 Node*	nod(int, Node*, Node*);
 Node*	nodlit(Val);