d: remove unnecessary methods from the Lexer interface

The complete symbol approach in yylex removes the need for the methods
semanticVal, startPos and endPos, which were used when the values were
reported separately.

* data/skeletons/lalr1.d: Here.
* doc/bison.texi: Remove sections about the three methods.
* examples/d/calc/calc.y, examples/d/simple/calc.y: Remove the unused methods.
* tests/calc.at, tests/d.at, tests/scanner.at: Test it.

tests/calc.at

@@ -565,22 +565,7 @@ class CalcLexer(R) : Lexer
 
   Value semanticVal_;]AT_LOCATION_IF([[
   Location location;
-
-  public final @property Position startPos()
-  {
-    return location.begin;
-  }
-
-  public final @property Position endPos()
-  {
-    return location.end;
-  }
 ]])[
-  public final @property Value semanticVal()
-  {
-    return semanticVal_;
-  }
-
   int parseInt ()
   {
     auto res = 0;

tests/d.at

@@ -79,7 +79,6 @@ class CalcLexer(R) : Lexer
   void yyerror(string s) {}
 
   Value semanticVal_;
-  Value semanticVal() @property { return semanticVal_; }
 
   Symbol yylex()
   {

tests/scanner.at

@@ -116,10 +116,6 @@ class YYLexer(R) : Lexer
   ]AT_YYERROR_DEFINE[
 
   Value semanticVal_;
-  public final @property Value semanticVal ()
-  {
-    return semanticVal_;
-  }
 
   Symbol yylex ()
   {