Add update Methods for Compilation Context

update method will allow the creation of a new compilation context
based on the current one with new types/names.

Signed-off-by: Will Hawkins <hawkinsw@obs.cr>

Sources/P4Compiler/Parser.swift

@@ -338,7 +338,7 @@ public struct Parser {
 
       // Parse a state in a nested scope.
       switch Parser.State.Compile(
-        node: parser_state, withContext: CompilerContext(withNames: current_context.names.enter()))
+        node: parser_state, withContext: context.update(newNames: current_context.names.enter()))
       {
       case Result.Ok(let (state, updated_context)):
         parser.states = parser.states.append(state: state)