Fix embedded (arm-none-eabi) builds

Due to OS#3360, build testing for arm-none-eabi was unfortunately
skipped for a long time.  This is a number of fixes that make the
compile test pass again.

Related: OS#3360
Change-Id: I88e3c8e1a8786ca2a6a023b0d27c74be200a8588
diff --git a/src/pseudotalloc/talloc.h b/src/pseudotalloc/talloc.h
index ae2e1fc..34088af 100644
--- a/src/pseudotalloc/talloc.h
+++ b/src/pseudotalloc/talloc.h
@@ -59,3 +59,6 @@
 			 unsigned count,
 			 const char *name);
 char *talloc_asprintf(const void *ctx, const char *fmt, ...);
+
+void *talloc_steal(const void *new_ctx, const void *obj);
+char *talloc_vasprintf(const void *t, const char *fmt, va_list ap);