Add calls to setmalloctag() in libc where it wraps
malloc and friends. This ensures leak(1) will point to
the buggy user code rather than the innocent library code.

-Steve

Reference: /n/sources/patch/applied/malloc-tags
Date: Fri Jan  4 17:22:16 CET 2013
Signed-off-by: steve@quintile.net

--- /sys/src/libc/fmt/runevsmprint.c	Fri Jan  4 17:17:36 2013
+++ /sys/src/libc/fmt/runevsmprint.c	Fri Jan  4 17:17:33 2013
@@ -38,6 +38,7 @@
 	f->start = malloc(sizeof(Rune)*n);
 	if(f->start == nil)
 		return -1;
+	setmalloctag(f->start, getcallerpc(&f));
 	f->to = f->start;
 	f->stop = (Rune*)f->start + n - 1;
 	f->flush = runeFmtStrFlush;
--- /sys/src/libc/fmt/vsmprint.c	Fri Jan  4 17:17:41 2013
+++ /sys/src/libc/fmt/vsmprint.c	Fri Jan  4 17:17:38 2013
@@ -38,6 +38,7 @@
 	f->start = malloc(n);
 	if(f->start == nil)
 		return -1;
+	setmalloctag(f->start, getcallerpc(&f));
 	f->to = f->start;
 	f->stop = (char*)f->start + n - 1;
 	f->flush = fmtStrFlush;
@@ -57,6 +58,7 @@
 
 	if(fmtstrinit(&f) < 0)
 		return nil;
+	setmalloctag(f.start, getcallerpc(&fmt));
 	f.args = args;
 	n = dofmt(&f, fmt);
 	if(f.start == nil)
--- /sys/src/libc/port/runestrdup.c	Fri Jan  4 17:17:47 2013
+++ /sys/src/libc/port/runestrdup.c	Fri Jan  4 17:17:43 2013
@@ -9,6 +9,7 @@
 	ns = malloc(sizeof(Rune)*(runestrlen(s) + 1));
 	if(ns == 0)
 		return 0;
+	setmalloctag(ns, getcallerpc(&s));
 
 	return runestrcpy(ns, s);
 }
--- /sys/src/libc/port/strdup.c	Fri Jan  4 17:17:52 2013
+++ /sys/src/libc/port/strdup.c	Fri Jan  4 17:17:49 2013
@@ -9,6 +9,7 @@
 	ns = malloc(strlen(s) + 1);
 	if(ns == 0)
 		return 0;
+	setmalloctag(ns, getcallerpc(&s));
 
 	return strcpy(ns, s);
 }