compiler, language, runtime: Separate Parser Type From Instances

In P4, parsers are considered types. Those parsers are instantiated.
The instantiated parsers are values. Previously, gp4 treated a parser
type and a parser value as identical. This PR makes that difference
clear _and_ sets the stage for the future.

TODO: Make the same distinction between control and action types and
values.

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

Tests/p4rseTests/InterloperTests.swift

@@ -47,7 +47,7 @@ import TreeSitterP4
     """
   
   let program = try #UseOkResult(Program.Compile(simple_parser_declaration))
-  let runtime = try #UseOkResult(P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
+  let runtime = try #UseOkResult(P4Runtime.Runtime<InstantiatedParserState, P4Lang.ParserValue>.create(program: program))
 
   var statements_executed: [String] = Array()
 
@@ -57,7 +57,9 @@ import TreeSitterP4
 
   let (state_result, _) = try! #UseOkResult(runtime.run(withArguments: ArgumentList(), inExecution: ProgramExecution(ev)))
 
-  #expect(AsInstantiatedParserState(state_result) == P4Lang.accept)
+  #expect(state_result == P4Lang.accept)
+
+  print("statements_executed: \(statements_executed)")
 
   #expect(statements_executed[0].hasPrefix("VariableDeclarationStatement"))
   #expect(statements_executed[1].hasPrefix("ParserAssignmentStatement"))
@@ -86,7 +88,7 @@ import TreeSitterP4
     """
   
   let program = try #UseOkResult(Program.Compile(simple_parser_declaration))
-  let runtime = try #UseOkResult(P4Runtime.Runtime<InstantiatedParserState, P4Lang.Parser>.create(program: program))
+  let runtime = try #UseOkResult(P4Runtime.Runtime<InstantiatedParserState, P4Lang.ParserValue>.create(program: program))
 
   var expressions_evaluated: [String] = Array()
 
@@ -96,7 +98,7 @@ import TreeSitterP4
 
   let (state_result, _) = try! #UseOkResult(runtime.run(withArguments: ArgumentList(), inExecution: ProgramExecution(ev)))
 
-  #expect(AsInstantiatedParserState(state_result) == P4Lang.accept)
+  #expect(state_result == P4Lang.accept)
 
   #expect(expressions_evaluated[0].hasPrefix("Value: true of Boolean"))
   #expect(expressions_evaluated[1].hasPrefix("Value: true of Boolean"))