feat(runtime-c-api) Extract the value module.

lib/runtime-c-api/src/value.rs

@@ -0,0 +1,29 @@
+//! Wasm values.
+
+use libc::{int32_t, int64_t};
+
+#[allow(non_camel_case_types)]
+#[repr(u32)]
+#[derive(Clone)]
+pub enum wasmer_value_tag {
+    WASM_I32,
+    WASM_I64,
+    WASM_F32,
+    WASM_F64,
+}
+
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub union wasmer_value {
+    pub I32: int32_t,
+    pub I64: int64_t,
+    pub F32: f32,
+    pub F64: f64,
+}
+
+#[repr(C)]
+#[derive(Clone)]
+pub struct wasmer_value_t {
+    pub tag: wasmer_value_tag,
+    pub value: wasmer_value,
+}