test: xfail-pretty some benchmarks. rs=burningtree

src/test/bench/graph500-bfs.rs

@@ -1,3 +1,5 @@
+// xfail-pretty
+
 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.

src/test/bench/sudoku.rs

@@ -1,3 +1,5 @@
+// xfail-pretty
+
 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.

src/test/bench/task-perf-jargon-metal-smoke.rs

@@ -1,3 +1,5 @@
+// xfail-pretty
+
 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.

src/test/bench/task-perf-linked-failure.rs

@@ -1,3 +1,5 @@
+// xfail-pretty
+
 // Copyright 2012 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.