Added a header generator for C and supporting CLI commands to invoke the generation of these headers

.vscode/settings.json

@@ -1,5 +1,8 @@
 {
     "rust-analyzer.runnables.extraTestBinaryArgs": [
         "--nocapture"
-    ]
-}
+    ],
+    "files.associations": {
+        "*.pli": "st"
+    }
+}

Cargo.toml

@@ -25,8 +25,8 @@ plc_index = { path = "./compiler/plc_index" }
 section_mangler = { path = "./compiler/section_mangler" }
 logos = "0.12.0"
 clap = { version = "3.0", features = ["derive"] }
-indexmap = "2.0"
-generational-arena = "0.2.8"
+indexmap = { version = "2.0", features = ["serde"] }
+generational-arena = { version = "0.2.8", features = ["serde"] }
 regex = "1"
 shell-words = "1.1.0"
 plc_derive = { path = "./compiler/plc_derive" }
@@ -79,6 +79,7 @@ members = [
     "compiler/plc_index",
     "compiler/section_mangler",
     "compiler/plc_lowering",
+    "compiler/plc_header_generator",
     "tests/test_utils",
 ]
 default-members = [".", "compiler/plc_driver", "compiler/plc_xml"]

compiler/plc_ast/Cargo.toml

@@ -9,6 +9,8 @@ edition = "2021"
 plc_util = { path = "../plc_util" }
 plc_source = { path = "../plc_source" }
 chrono = { version = "0.4", default-features = false }
-serde = { version = "1.0", features = ["derive"] }
+# Enabled the RC feature (for Arc<T>) see: https://serde.rs/feature-flags.html#-features-rc
+serde = { version = "1.0", features = ["derive", "rc"] }
+serde_json.workspace = true
 derive_more = { version = "0.99.0", features = ["try_into"] }
 rustc-hash.workspace = true