Add regression test to close #56100

Author: AnthonyLatsis

validation-test/compiler_crashers_2_fixed/sr13703.swift

@@ -0,0 +1,9 @@
+// RUN: %swift-ide-test -code-completion -code-completion-token=COMPLETE -source-filename %s
+
+extension Result {
+  public init(_ value: Success?) {
+    self = value.map(#^COMPLETE^#)
+  }
+}
+
+public func materialize<T>(_ f: T) {}