[Tests] Pre split test files

split_files.py changes the newline characters depending on the platform

Author: rintaro

test/Serialization/Inputs/SourceInfo/File1.swift

@@ -0,0 +1,2 @@
+public func foo(val: MyStruct) {
+}

test/Serialization/Inputs/SourceInfo/File2.swift

@@ -0,0 +1,4 @@
+public struct MyStruct {
+    var x: Int
+    var y: Int
+}

test/Serialization/sourceinfo.swift

@@ -1,22 +1,10 @@
-// BEGIN File1.swift
-public func foo(val: MyStruct) {
-}
-
-// BEGIN File2.swift
-public struct MyStruct {
-    var x: Int
-    var y: Int
-}
-
-// BEGIN DUMMY.swift
 import MyModule
 
 // RUN: %empty-directory(%t)
 // RUN: %empty-directory(%t/Modules)
-// RUN: %{python} %utils/split_file.py -o %t %s
 
-// RUN: %target-swiftc_driver -emit-module -module-name MyModule -o %t/Modules/MyModule.swiftmodule %t/File1.swift %t/File2.swift
-// RUN: %swift-ide-test -print-module-metadata -module-to-print MyModule -enable-swiftsourceinfo -I %t/Modules -source-filename %t/DUMMY.swift | %FileCheck %s
+// RUN: %target-swiftc_driver -emit-module -module-name MyModule -o %t/Modules/MyModule.swiftmodule %S/Inputs/SourceInfo/File1.swift %S/Inputs/SourceInfo/File2.swift
+// RUN: %target-swift-ide-test -print-module-metadata -module-to-print MyModule -enable-swiftsourceinfo -I %t/Modules -source-filename %s | %FileCheck %s
 
-// CHECK: filepath=BUILD_DIR/{{.*}}/File1.swift; hash=b44bab617797a7239a9fa948f11eb90b; mtime={{[0-9]{4}-[0-9]{2}-[0-9]{2} .*}}; size=36
-// CHECK: filepath=BUILD_DIR/{{.*}}/File2.swift; hash=c989d6b98d505a1f52749d43ea0569a1; mtime={{[0-9]{4}-[0-9]{2}-[0-9]{2} .*}}; size=58
+// CHECK: filepath=SOURCE_DIR{{[/\\]}}test{{[/\\]}}Serialization{{[/\\]}}Inputs{{[/\\]}}SourceInfo{{[/\\]}}File1.swift; hash=b44bab617797a7239a9fa948f11eb90b; mtime={{[0-9]{4}-[0-9]{2}-[0-9]{2} .*}}; size=35
+// CHECK: filepath=SOURCE_DIR{{[/\\]}}test{{[/\\]}}Serialization{{[/\\]}}Inputs{{[/\\]}}SourceInfo{{[/\\]}}File2.swift; hash=c989d6b98d505a1f52749d43ea0569a1; mtime={{[0-9]{4}-[0-9]{2}-[0-9]{2} .*}}; size=57