Merge pull request #2557 from dduan/add_enum_crasher

[crasher] add a crasher

Author: dduan

validation-test/compiler_crashers_2/0044-enum-dot-crash.swift

@@ -0,0 +1,7 @@
+// RUN: not --crash %target-swift-frontend %s -emit-silgen
+
+enum X {
+    init?(a: Int) {
+        .p[a]
+    }
+}