Use runtime clang-sys feature to match cpal

I was getting the following `clang-sys` failure when using `vst3-bindgen` in a
crate that also depends on `cpal`:

```
  thread 'main' panicked at 'a `libclang` shared library is not loaded on this thread', /Users/kevin/.cargo/registry/src/index.crates.io-6f17d22bba15001f/clang-sys-1.6.1/src/lib.rs:1735:1
```

I think `cpal`'s transitive dependency on `clang-sys` enables the runtime
feature, also enabling it for `com-scrape`'s usage of `clang-sys`. But
`clang_sys::load()` must be called when the runtime feature is enabled.

Author: kcking

com-scrape/Cargo.toml

@@ -1,11 +1,11 @@
-[package]
-name = "com-scrape"
-version = "0.1.0"
-authors = ["Micah Johnston <[email protected]>"]
-edition = "2021"
-description = "Automatically generates Rust bindings for COM interfaces"
-repository = "https://github.com/coupler-rs/vst3-bindgen"
-license = "MIT OR Apache-2.0"
-
-[dependencies]
-clang-sys = { version = "1", features = ["clang_6_0"] }
+[package]
+name = "com-scrape"
+version = "0.1.0"
+authors = ["Micah Johnston <[email protected]>"]
+edition = "2021"
+description = "Automatically generates Rust bindings for COM interfaces"
+repository = "https://github.com/coupler-rs/vst3-bindgen"
+license = "MIT OR Apache-2.0"
+
+[dependencies]
+clang-sys = { version = "1", features = ["clang_6_0", "runtime"] }

com-scrape/src/generator.rs

@@ -53,6 +53,7 @@ pub struct Generator {
 
 impl Generator {
     pub fn new() -> Self {
+        clang_sys::load().unwrap();
         Generator {
             options: GeneratorOptions::default(),
             source: String::new(),