Merge pull request #1085 from practicalswift/swiftc-28237-swift-archetypebuilder-addgenericparameter

[swiftc] Add test case for crash triggered in swift::ArchetypeBuilder::addGenericParameter(…)

Author: gribozavr

validation-test/compiler_crashers/28237-swift-archetypebuilder-addgenericparameter.swift

@@ -0,0 +1,8 @@
+// RUN: not --crash %target-swift-frontend %s -parse
+// REQUIRES: asserts
+
+// Distributed under the terms of the MIT license
+// Test case submitted to project by https://github.com/practicalswift (practicalswift)
+// Test case found by fuzzing
+
+{<f}class B<a{protocol a{enum S<A{extension{protocol a{func<