Fold runtime/ crate into this source tree

While I like the idea of having a runtime completely decoupled from the
syntax and compiler, I don't think this is that big of a project for
that to be necessary or even useful yet.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

src/vm/mod.rs

@@ -0,0 +1,52 @@
+mod frame;
+pub mod inst;
+pub mod consts;
+
+use crate::obj::prelude::*;
+
+use frame::*;
+
+#[derive(Debug)]
+pub struct Vm {
+    stack: Vec<ObjRef>,
+    frames: Vec<Frame>,
+    pc: usize,
+    condition: bool,
+}
+
+impl Vm {
+    pub fn new() -> Self {
+        Self {
+            stack: Default::default(),
+            frames: vec![Default::default()], // Start with a root stack frame
+            pc: 0,
+            condition: false,
+        }
+    }
+
+    pub fn stack(&self) -> &Vec<ObjRef> {
+        &self.stack
+    }
+
+    pub fn stack_mut(&mut self) -> &mut Vec<ObjRef> {
+        &mut self.stack
+    }
+
+    pub fn push(&mut self, value: ObjRef) {
+        self.stack_mut().push(value);
+    }
+
+    pub fn pop(&mut self) -> Option<ObjRef> {
+        self.stack_mut().pop()
+    }
+
+    pub fn pc(&self) -> usize {
+        self.pc
+    }
+
+    pub fn condition(&self) -> bool {
+        self.condition
+    }
+
+    //pub fn new_local(&mut self, name: String, 
+}