Revert "[StdLib] Extend ReflectionHashing test to pass on Linux"

This test expects consistent hash code generation on any given platform.
However String instance generate different values on Linux depending on which
version of libicu is installed, causing environment-specific test failures.

This reverts commit def419b.

Author: Emanuel Zephir

test/1_stdlib/ReflectionHashing.swift

@@ -2,6 +2,8 @@
 // RUN: %target-run %t.out
 // REQUIRES: executable_test
 
+// XFAIL: linux
+
 //
 // This file contains reflection tests that depend on hash values.
 // Don't add other tests here.
@@ -36,7 +38,7 @@ Reflection.test("Dictionary") {
   var output = ""
   dump(dict, &output)
 
-#if _runtime(_ObjC) && (arch(i386) || arch(arm))
+#if arch(i386) || arch(arm)
   var expected = ""
   expected += "▿ 5 key/value pairs\n"
   expected += "  ▿ [0]: (2 elements)\n"
@@ -54,7 +56,7 @@ Reflection.test("Dictionary") {
   expected += "  ▿ [4]: (2 elements)\n"
   expected += "    - .0: Three\n"
   expected += "    - .1: 3\n"
-#elseif _runtime(_ObjC) && (arch(x86_64) || arch(arm64))
+#elseif arch(x86_64) || arch(arm64)
   var expected = ""
   expected += "▿ 5 key/value pairs\n"
   expected += "  ▿ [0]: (2 elements)\n"
@@ -72,24 +74,6 @@ Reflection.test("Dictionary") {
   expected += "  ▿ [4]: (2 elements)\n"
   expected += "    - .0: Four\n"
   expected += "    - .1: 4\n"
-#elseif !_runtime(_ObjC) && arch(x86_64)
-  var expected = ""
-  expected += "▿ 5 key/value pairs\n"
-  expected += "  ▿ [0]: (2 elements)\n"
-  expected += "    - .0: One\n"
-  expected += "    - .1: 1\n"
-  expected += "  ▿ [1]: (2 elements)\n"
-  expected += "    - .0: Five\n"
-  expected += "    - .1: 5\n"
-  expected += "  ▿ [2]: (2 elements)\n"
-  expected += "    - .0: Two\n"
-  expected += "    - .1: 2\n"
-  expected += "  ▿ [3]: (2 elements)\n"
-  expected += "    - .0: Four\n"
-  expected += "    - .1: 4\n"
-  expected += "  ▿ [4]: (2 elements)\n"
-  expected += "    - .0: Three\n"
-  expected += "    - .1: 3\n"
 #else
   fatalError("unimplemented")
 #endif