Remove deprecated messaget() constructor

It is now no longer possible to construct a messaget object that is not
fully configured, i.e., lacks a message handler.

src/util/message.h

@@ -15,7 +15,6 @@ Author: Daniel Kroening, [email protected]
 #include <sstream>
 #include <string>
 
-#include "deprecate.h"
 #include "invariant.h"
 #include "source_location.h"
 
@@ -191,13 +190,6 @@ class messaget
 
   // constructors, destructor
 
-  DEPRECATED(SINCE(2019, 1, 7, "use messaget(message_handler) instead"))
-  messaget():
-    message_handler(nullptr),
-    mstream(M_DEBUG, *this)
-  {
-  }
-
   messaget(const messaget &other):
     message_handler(other.message_handler),
     mstream(other.mstream, *this)

src/util/parser.h

@@ -12,7 +12,6 @@ Author: Daniel Kroening, [email protected]
 #ifndef CPROVER_UTIL_PARSER_H
 #define CPROVER_UTIL_PARSER_H
 
-#include "deprecate.h"
 #include "expr.h"
 #include "message.h"
 
@@ -40,8 +39,6 @@ class parsert
     last_line.clear();
   }
 
-  DEPRECATED(SINCE(2023, 12, 20, "use parsert(message_handler) instead"))
-  parsert():in(nullptr) { clear(); }
   explicit parsert(message_handlert &message_handler)
     : in(nullptr), log(message_handler)
   {
@@ -138,11 +135,8 @@ class parsert
     column+=token_width;
   }
 
-  // should be protected or even just be a reference to a message handler, but
-  // for now enables a step-by-step transition
-  messaget log;
-
 protected:
+  messaget log;
   source_locationt source_location;
   unsigned line_no, previous_line_no;
   unsigned column;