[test] Let test output go to stdout.

...so we can see it in failure logs.

Author: jrose-apple

test/stdlib/TestData.swift

@@ -12,7 +12,7 @@
 // RUN: %target-clang %S/Inputs/FoundationBridge/FoundationBridge.m -c -o %t/FoundationBridgeObjC.o -g
 // RUN: %target-build-swift %s -I %S/Inputs/FoundationBridge/ -Xlinker %t/FoundationBridgeObjC.o -o %t/TestData
 
-// RUN: %target-run %t/TestData > %t.txt
+// RUN: %target-run %t/TestData
 // REQUIRES: executable_test
 // REQUIRES: objc_interop