add test case for issue#6571

Author: ding-young

tests/source/crash-on-enum-generics/issue_6571.rs

@@ -0,0 +1,14 @@
+pub enum TestEnum<
+    T: std::collections::HashMap<String, Vec<Box<dyn std::fmt::Debug + Send + Sync + 'static>>> + Clone + Default + PartialEq + Eq + std::fmt::Debug + serde::Serialize + serde::Deserialize<'static> + Send + Sync + 'static = std::collections::HashMap<String, Vec<Box<dyn std::fmt::Debug + Send + Sync + 'static>>>,
+> {
+    Variant1(T),
+    Variant2 { field: T },
+}
+
+// More realistic example from real codebase
+pub enum ElementInit<
+    P: wrt_foundation::MemoryProvider + Clone + Default + PartialEq + Eq = wrt_foundation::NoStdProvider<1024>,
+> {
+    FuncIndices(crate::WasmVec<u32, P>),
+    Expressions(crate::WasmVec<crate::WasmVec<u8, P>, P>),
+}

tests/target/crash-on-enum-generics/issue_6571.rs

@@ -0,0 +1,14 @@
+pub enum TestEnum<
+    T: std::collections::HashMap<String, Vec<Box<dyn std::fmt::Debug + Send + Sync + 'static>>> + Clone + Default + PartialEq + Eq + std::fmt::Debug + serde::Serialize + serde::Deserialize<'static> + Send + Sync + 'static = std::collections::HashMap<String, Vec<Box<dyn std::fmt::Debug + Send + Sync + 'static>>>,
+> {
+    Variant1(T),
+    Variant2 { field: T },
+}
+
+// More realistic example from real codebase
+pub enum ElementInit<
+    P: wrt_foundation::MemoryProvider + Clone + Default + PartialEq + Eq = wrt_foundation::NoStdProvider<1024>,
+> {
+    FuncIndices(crate::WasmVec<u32, P>),
+    Expressions(crate::WasmVec<crate::WasmVec<u8, P>, P>),
+}