Correct source data for test data of NSString file initialization and add the resource to the copy resources phase for linux

Author: phausler

TestFoundation/Resources/NSStringTestData.txt

@@ -1 +1 @@
-swift-corelibs-foundation
+swift-corelibs-foundation

build.py

@@ -349,6 +349,7 @@
     'TestFoundation/Resources/Info.plist',
     'TestFoundation/Resources/NSURLTestData.plist',
     'TestFoundation/Resources/Test.plist',
+    'TestFoundation/Resources/NSStringTestData.txt',
 ])
 
 # TODO: Probably this should be another 'product', but for now it's simply a phase