feat: add a histrical wit-bindgen

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

@@ -0,0 +1,57 @@
+/// A union of all of the integral types
+union all-integers {
+    /// Bool is equivalent to a 1 bit integer
+    /// and is treated that way in some languages
+    bool,
+    u8, u16, u32, u64,
+    s8, s16, s32, s64
+}
+union all-floats {
+    float32, float64
+}
+union all-text {
+    char, string
+}
+
+// Returns the same case as the input but with 1 added
+add-one-integer: func(num: all-integers) -> all-integers
+// Returns the same case as the input but with 1 added
+add-one-float: func(num: all-floats) -> all-floats
+// Returns the same case as the input but with the first character replaced
+replace-first-char: func(text: all-text, letter: char) -> all-text
+
+// Returns the index of the case provided
+identify-integer: func(num: all-integers) -> u8
+// Returns the index of the case provided
+identify-float: func(num: all-floats) -> u8
+// Returns the index of the case provided
+identify-text: func(text: all-text) -> u8
+
+union duplicated-s32 {
+    /// The first s32
+    s32,
+    /// The second s32
+    s32,
+    /// The third s32
+    s32
+}
+
+// Returns the same case as the input but with 1 added
+add-one-duplicated: func(num: duplicated-s32) -> duplicated-s32
+
+// Returns the index of the case provided
+identify-duplicated: func(num: duplicated-s32) -> u8
+
+/// A type containing numeric types that are distinct in most languages
+union distinguishable-num {
+    /// A Floating Point Number
+    float64,
+    /// A Signed Integer
+    s64
+}
+
+// Returns the same case as the input but with 1 added
+add-one-distinguishable-num: func(num: distinguishable-num) -> distinguishable-num
+
+// Returns the index of the case provided
+identify-distinguishable-num: func(num: distinguishable-num) -> u8