Use quiet tests by default

config.toml.example

@@ -303,7 +303,7 @@
 
 # Suppresses extraneous output from tests to ensure the output of the test
 # harness is relatively clean.
-#quiet-tests = false
+#quiet-tests = true
 
 # Flag indicating whether tests are compiled with optimizations (the -O flag) or
 # with debuginfo (the -g flag)

src/bootstrap/config.rs

@@ -347,6 +347,7 @@ impl Config {
         config.backtrace = true;
         config.rust_optimize = true;
         config.rust_optimize_tests = true;
+        config.quiet_tests = true;
         config.submodules = true;
         config.fast_submodules = true;
         config.docs = true;