Merge pull request #8229 from slavapestov/another-protocol-typealias-crasher-yay

Add another crasher with protocol typealiases

Author: slavapestov

validation-test/compiler_crashers_2/0084-rdar31093854.swift

@@ -0,0 +1,19 @@
+// RUN: not --crash %target-swift-frontend -swift-version 4 %s -typecheck -o /dev/null
+
+// This should actually type check successfully.
+
+protocol P {
+  associatedtype T
+}
+
+protocol Q1 : P {
+  typealias T = Int
+
+  func f(_: T)
+}
+
+protocol Q2 : P {
+  associatedtype T where T == Int
+
+  func f(_: T)
+}