Imported Upstream version 5.18.0.179

Former-commit-id: 67aa10e65b237e1c4537630979ee99ebe1374215

external/llvm/test/Transforms/LowerSwitch/delete-default-block-crash.ll

@@ -0,0 +1,27 @@
+; RUN: opt < %s -lowerswitch -disable-output
+
+; This test verify -lowerswitch does not crash after deleting the default block.
+
+declare i32 @f(i32)
+
+define i32 @unreachable(i32 %x) {
+
+entry:
+  switch i32 %x, label %unreachable [
+    i32 5, label %a
+    i32 6, label %a
+    i32 7, label %a
+    i32 10, label %b
+    i32 20, label %b
+    i32 30, label %b
+    i32 40, label %b
+  ]
+unreachable:
+  unreachable
+a:
+  %0 = call i32 @f(i32 0)
+  ret i32 %0
+b:
+  %1 = call i32 @f(i32 1)
+  ret i32 %1
+}