cobol: Do not include C++ headers after system.h.

The headers mentioned in parse.y are already unconditionally included
by system.h (via cobol-system.h).

gcc/cobol/ChangeLog:

	* parse.y: Remove c++ header includes appearing after
	system.h.

Signed-off-by: Iain Sandoe <iain@sandoe.co.uk>

gcc/cobol/parse.y

@@ -30,9 +30,6 @@
 %code requires {
   #include <fstream>  // Before cobol-system because it uses poisoned functions
   #include "cobol-system.h"
-  #include <cmath>
-  #include <algorithm>
-  #include <map>
   #include "../../libgcobol/io.h"
   #include "../../libgcobol/ec.h"
 
@@ -216,9 +213,6 @@
   new_literal( const char initial[], enum radix_t radix );
 #pragma GCC diagnostic pop
 
-
-  #include <list>
-
   enum select_clause_t {
     access_clause_e        = 0x0001,
     alt_key_clause_e       = 0x0002,