Rename "Local" to "Name" when referring to variables during compilation

* Variables were previously named "Local"s because they described a
  local variable - however, this is kind of a misnomer because it
  handles globals as well. This has been changed pretty much everywhere
  when appropriate (hopefully).
* Renamed obj/names.rs to obj/reserved.rs, freeing up the "names" module
  for the new Names handle
* Renamed obj/locals.rs to obj/names.rs, see above

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

src/vm/inst.rs

@@ -10,10 +10,10 @@ pub enum Inst {
     PushConst(ConstHandle),
 
     /// Looks up and pushes a local value.
-    PushLocal(Local),
+    LoadName(Name),
 
     /// Pop a value from the stack, possibly into a local symbol.
-    Pop(Option<Local>),
+    Pop(Option<Name>),
 
     /// Pops a symbol value and an object reference.
     ///
@@ -119,7 +119,7 @@ impl Inst {
         match self {
             Inst::PushSym(_) => "PUSH_SYM",
             Inst::PushConst(_) => "PUSH_CONST",
-            Inst::PushLocal(_) => "PUSH_LOCAL",
+            Inst::LoadName(_) => "LOAD_NAME",
             Inst::Pop(_) => "POP",
             Inst::GetAttr(_) => "GET_ATTR",
             Inst::SetAttr(_) => "SET_ATTR",
@@ -189,7 +189,7 @@ impl Display for InstFormatter<'_, '_> {
                         format!("{:?}", obj)
                     },
                 ),
-                Inst::PushLocal(local) => (
+                Inst::LoadName(local) => (
                     local.index().to_string(),
                     "TODO: local name".to_string(),
                 ),