diff --git a/validation-test/IRGen/rdar136388508.swift b/validation-test/IRGen/rdar136388508.swift
new file mode 100644
index 0000000000000..ddfbdbce7022e
--- /dev/null
+++ b/validation-test/IRGen/rdar136388508.swift
@@ -0,0 +1,27 @@
+// RUN: %target-swiftc_driver -c -O %s
+
+// This used to crash during LargeTypesReg2Mem.
+
+class C {}
+struct Big {
+  let c: C
+  let x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15, x16, x17, x18, x19, x20: Int
+  @_silgen_name("Big.init")
+  init(_ bool: Bool)
+}
+
+@_silgen_name("summon")
+func summon<Entity>() throws -> Entity
+@_silgen_name("banish")
+func banish<Entity>(_ t: Entity)
+
+func doit() {
+  let big: Big
+  do {
+      big = Big(try summon())
+      
+      banish(try summon() as Bool)
+  } catch {
+      _ = "\(error)"
+  }
+}