fix xargo with newer libstd

RalfJung · RalfJung · commit 55f32668e717 · 2017-05-24T21:00:54.000-07:00
diff --git a/xargo/Xargo.toml b/xargo/Xargo.toml
@@ -1,2 +1,2 @@
 [dependencies]
-std = {features = ["panic_unwind", "jemalloc"]}
+std = {features = ["panic_unwind", "jemalloc", "backtrace"]}

Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,2 @@`
`1`	`1`	`[dependencies]`
`2`		`-std = {features = ["panic_unwind", "jemalloc"]}`
	`2`	`+std = {features = ["panic_unwind", "jemalloc", "backtrace"]}`