Merge pull request #25475 from benlangmuir/disable-modelio-51

[5.1] Temporarily disable validation-test/stdlib/ModelIO.swift

Author: benlangmuir

validation-test/stdlib/ModelIO.swift

@@ -11,7 +11,8 @@ import ModelIO
 var ModelIOTests = TestSuite("ModelIO")
 
 if #available(OSX 10.13, iOS 11.0, tvOS 11.0, *) {
-    ModelIOTests.test("MDLAnimatedScalar/accessors") {
+    ModelIOTests.test("MDLAnimatedScalar/accessors")
+    .skip(.always("rdar://problem/50449570")).code {
         let animatedVal = MDLAnimatedScalar()
         let testCount = 10
         let testTimeVal = 5.0