feat: add a histrical wit-bindgen

__wasm/wit-bindgen-sample/wit-bindgen/tests/codegen/variants.wit

@@ -0,0 +1,135 @@
+enum e1 {
+    a,
+}
+
+e1-arg: func(x: e1)
+e1-result: func() -> e1
+
+union u1 {
+    u32,
+    float32,
+}
+
+u1-arg: func(x: u1)
+u1-result: func() -> u1
+
+record empty {}
+
+variant v1 {
+    a,
+    b(u1),
+    c(e1),
+    d(string),
+    e(empty),
+    f,
+    g(u32),
+}
+
+v1-arg: func(x: v1)
+v1-result: func() -> v1
+
+bool-arg: func(x: bool)
+bool-result: func() -> bool
+
+option-arg: func(
+  a: option<bool>,
+  b: option<tuple<>>,
+  c: option<u32>,
+  d: option<e1>,
+  e: option<float32>,
+  f: option<u1>,
+  g: option<option<bool>>,
+)
+option-result: func() -> tuple<
+  option<bool>,
+  option<tuple<>>,
+  option<u32>,
+  option<e1>,
+  option<float32>,
+  option<u1>,
+  option<option<bool>>,
+>
+
+variant casts1 {
+  a(s32),
+  b(float32),
+}
+
+variant casts2 {
+  a(float64),
+  b(float32),
+}
+
+variant casts3 {
+  a(float64),
+  b(u64),
+}
+
+variant casts4 {
+  a(u32),
+  b(s64),
+}
+
+variant casts5 {
+  a(float32),
+  b(s64),
+}
+
+variant casts6 {
+  a(tuple<float32, u32>),
+  b(tuple<u32, u32>),
+}
+
+casts: func(
+  a: casts1,
+  b: casts2,
+  c: casts3,
+  d: casts4,
+  e: casts5,
+  f: casts6,
+) -> tuple<
+  casts1,
+  casts2,
+  casts3,
+  casts4,
+  casts5,
+  casts6,
+>
+
+expected-arg: func(
+  a: expected<unit, unit>,
+  b: expected<unit, e1>,
+  c: expected<e1, unit>,
+  d: expected<tuple<>, tuple<>>,
+  e: expected<u32, v1>,
+  f: expected<string, list<u8>>,
+)
+expected-result: func() -> tuple<
+  expected<unit, unit>,
+  expected<unit, e1>,
+  expected<e1, unit>,
+  expected<tuple<>, tuple<>>,
+  expected<u32, v1>,
+  expected<string, list<u8>>,
+>
+
+enum my-errno {
+  bad1,
+  bad2,
+}
+
+return-expected-sugar: func() -> expected<s32, my-errno>
+return-expected-sugar2: func() -> expected<unit, my-errno>
+return-expected-sugar3: func() -> expected<my-errno, my-errno>
+return-expected-sugar4: func() -> expected<tuple<s32, u32>, my-errno>
+return-option-sugar: func() -> option<s32>
+return-option-sugar2: func() -> option<my-errno>
+
+expected-simple: func() -> expected<u32, s32>
+
+record is-clone {
+  v1: v1,
+}
+
+is-clone-arg: func(a: is-clone)
+is-clone-return: func() -> is-clone