Rename old crash cases to match the current naming scheme.

Will allow for easy import of crash cases from swift-compiler-crashes.

validation-test/compiler_crashers_fixed/00618-swift-parser-parseexprsequence.swift

@@ -0,0 +1,18 @@
+// RUN: not %target-swift-frontend %s -parse
+
+// Distributed under the terms of the MIT license
+// Test case submitted to project by https://github.com/practicalswift (practicalswift)
+// Test case found by fuzzing
+
+func e<l {
+n<n : l,) {
+}
+) -> (m, m -> m) -> m {
+e c e.i = {
+}
+{
+m) {
+n  }
+}
+protoco}
+class e: f{  class f