Disable liveness "dead" instruction by default.

The liveness instruction take up about 10% of the bytecode bloat file.
It is not very useful, it is duplicate information can be obtain
from the def/user chain.

This change disable the liveness instruction by default.
The caller can track_pseudo_death() if needed.

Signed-Off-By: Christopher Li <sparse@chrisli.org>

Index: sparse/lib.c
===================================================================
--- sparse.orig/lib.c	2007-02-02 16:03:32.000000000 -0800
+++ sparse/lib.c	2007-02-02 16:06:25.000000000 -0800
@@ -191,7 +191,8 @@ int Wenum_mismatch = 1;
 int Wdo_while = 1;
 int Wuninitialized = 1;
 
-int dbg_entry;
+int dbg_entry = 0;
+int dbg_dead = 0;
 
 int preprocess_only;
 char *include;
@@ -391,6 +392,7 @@ static char **handle_switch_W(char *arg,
 
 static struct warning debugs[] = {
 	{ "entry", &dbg_entry},
+	{ "dead", &dbg_dead},
 };
 
 
Index: sparse/example.c
===================================================================
--- sparse.orig/example.c	2007-02-02 16:00:51.000000000 -0800
+++ sparse/example.c	2007-02-02 16:06:02.000000000 -0800
@@ -1946,6 +1946,7 @@ int main(int argc, char **argv)
 	char *file;
 
 	compile(sparse_initialize(argc, argv, &filelist));
+	dbg_dead = 1;
 	FOR_EACH_PTR_NOTAG(filelist, file) {
 		compile(sparse(file));
 	} END_FOR_EACH_PTR_NOTAG(file);
Index: sparse/lib.h
===================================================================
--- sparse.orig/lib.h	2007-02-02 16:04:07.000000000 -0800
+++ sparse/lib.h	2007-02-02 16:04:46.000000000 -0800
@@ -98,6 +98,7 @@ extern int Wdo_while;
 extern int Wuninitialized;
 
 extern int dbg_entry;
+extern int dbg_dead;
 
 extern void declare_builtin_functions(void);
 extern void create_builtin_stream(void);
Index: sparse/linearize.c
===================================================================
--- sparse.orig/linearize.c	2007-02-02 16:00:51.000000000 -0800
+++ sparse/linearize.c	2007-02-02 16:05:15.000000000 -0800
@@ -2134,7 +2134,8 @@ repeat:
 	}
 
 	/* Finally, add deathnotes to pseudos now that we have them */
-	track_pseudo_death(ep);
+	if (dbg_dead)
+		track_pseudo_death(ep);
 
 	return ep;
 }