chore(defunctionalize): Add regression test for missing lambda variants panic

test_programs/compile_success_empty/lambda_call_assign_in_lambda/Nargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "lambda_call_assign_in_lambda"
+type = "bin"
+authors = [""]
+
+[dependencies]

test_programs/compile_success_empty/lambda_call_assign_in_lambda/src/main.nr

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+// Regression for issue #5212 (https://github.com/noir-lang/noir/issues/5212)
+fn main() {
+    let lambda1 = || 1;
+
+    // Previous bug: Compiler panic when you create a variable in a lambda with another lambda call as its value
+    let _ = || { let _: u8 = lambda1(); };
+
+    // No panic if the variable is created before we assign its value as the lambda call
+    let _ = || {
+        let mut var3: u8 = 1;
+        var3 = lambda1();
+    };
+
+    // No panic with a function call that has the same behavior
+    let _ = || { let _: u8 = func(); };
+
+    // No panic outside a lambda code block
+    let _: u8 = lambda1();
+}
+
+fn func() -> u8 {
+    1
+}