Remove unused includes in ada-*.c files

include-what-you-use reports:

../../../src/binutils-gdb/gdb/ada-lang.c should remove these lines:
- #include <sys/stat.h>  // lines 43-43
- #include <map>  // lines 66-66
- #include "c-lang.h"  // lines 33-33
- #include "demangle.h"  // lines 23-23
- #include "dictionary.h"  // lines 47-47
- #include "gdbsupport/gdb_vecs.h"  // lines 53-53
- #include "psymtab.h"  // lines 58-58

../../../src/binutils-gdb/gdb/ada-lang.c should remove these lines:
- #include <sys/stat.h>  // lines 43-43
- #include <map>  // lines 66-66
- #include "c-lang.h"  // lines 33-33
- #include "demangle.h"  // lines 23-23
- #include "dictionary.h"  // lines 47-47
- #include "gdbsupport/gdb_vecs.h"  // lines 53-53
- #include "psymtab.h"  // lines 58-58

../../../src/binutils-gdb/gdb/ada-valprint.c should remove these lines:
- #include "c-lang.h"  // lines 31-31
- #include "demangle.h"  // lines 26-26
- #include "infcall.h"  // lines 32-32
- #include "objfiles.h"  // lines 33-33
- #include "symtab.h"  // lines 22-22

Remove these includes.  Adding an include for gdbarch.h in
ada-valprint.c was necessary, because gdbarch_byte_order wouldn't be
found anymore.

gdb/ChangeLog:

	* ada-lang.c: Remove includes.
	* ada-typeprint.c: Remove includes.
	* ada-valprint.c: Remove includes.

Change-Id: I07c2f2237ef0ed5fd9aa855d33711d780794fce2

gdb/ada-lang.c

@@ -20,7 +20,6 @@
 
 #include "defs.h"
 #include <ctype.h>
-#include "demangle.h"
 #include "gdb_regex.h"
 #include "frame.h"
 #include "symtab.h"
@@ -30,7 +29,6 @@
 #include "parser-defs.h"
 #include "language.h"
 #include "varobj.h"
-#include "c-lang.h"
 #include "inferior.h"
 #include "symfile.h"
 #include "objfiles.h"
@@ -40,22 +38,18 @@
 #include "gdb_obstack.h"
 #include "ada-lang.h"
 #include "completer.h"
-#include <sys/stat.h>
 #include "ui-out.h"
 #include "block.h"
 #include "infcall.h"
-#include "dictionary.h"
 #include "annotate.h"
 #include "valprint.h"
 #include "source.h"
 #include "observable.h"
 #include "stack.h"
-#include "gdbsupport/gdb_vecs.h"
 #include "typeprint.h"
 #include "namespace.h"
 #include "cli/cli-style.h"
 
-#include "psymtab.h"
 #include "value.h"
 #include "mi/mi-common.h"
 #include "arch-utils.h"
@@ -63,7 +57,6 @@
 #include "gdbsupport/function-view.h"
 #include "gdbsupport/byte-vector.h"
 #include <algorithm>
-#include <map>
 
 /* Define whether or not the C operator '/' truncates towards zero for
    differently signed operands (truncation direction is undefined in C).