fix rust bindings build on windows (#1584)

Refine rust bindings.

Cargo.toml

@@ -0,0 +1,44 @@
+[package]
+name = "unicorn-engine"
+version = "2.0.0-rc6"
+authors = ["Ziqiao Kong", "Lukas Seidel"]
+documentation = "https://github.com/unicorn-engine/unicorn/wiki"
+edition = "2021"
+license = "GPL-2.0"
+readme = "README.md"
+repository = "https://github.com/unicorn-engine/unicorn"
+description = "Rust bindings for the Unicorn emulator with utility functions"
+build = "bindings/rust/build.rs"
+links = "unicorn"
+# use `cargo publish --list` to see files to be included
+# the resulting list what cargo uses to check for out-of-date files during build
+exclude = [
+    "/docs",
+    "/bindings/dotnet",
+    "/bindings/go",
+    "/bindings/haskell",
+    "/bindings/java",
+    "/bindings/pascal",
+    "/bindings/python",
+    "/bindings/ruby",
+    "/bindings/vb6",
+    "/samples",
+    "/tests",
+]
+
+[lib]
+path = "bindings/rust/src/lib.rs"
+
+[dependencies]
+bitflags = "1.3"
+libc = "0.2"
+
+[build-dependencies]
+cc = { optional = true, version = "1.0" }
+cmake = { optional = true, version = "0.1" }
+pkg-config = { optional = true, version = "0.3" }
+
+[features]
+default = ["build_unicorn_cmake"]
+build_unicorn_cmake = ["cc", "cmake"]
+use_system_unicorn = ["pkg-config"]