gdb: remove unused includes from dwarf2read.c

include-what-you-use says:

../../../src/binutils-gdb/gdb/dwarf2read.c should remove these lines:
- #include <ctype.h>  // lines 67-67
- #include <sys/stat.h>  // lines 59-59
- #include <sys/types.h>  // lines 83-83
- #include <cmath>  // lines 88-88
- #include <forward_list>  // lines 90-90
- #include <set>  // lines 89-89
- #include <unordered_set>  // lines 85-85
- #include "completer.h"  // lines 60-60
- #include "expression.h"  // lines 44-44
- #include "gdbsupport/byte-vector.h"  // lines 78-78
- #include "gdbsupport/filestuff.h"  // lines 71-71
- #include "gdbsupport/gdb_unlinker.h"  // lines 74-74

After a quick glance, that makes sense, so this patch removes them.

gdb/ChangeLog:

	* dwarf2read.c: Remove includes.

Change-Id: I13cfcb2f1d747144fddba7f66b329630b79dae90

gdb/ChangeLog

@@ -1,3 +1,7 @@
+2019-10-14  Simon Marchi  <simon.marchi@polymtl.ca>
+
+	* dwarf2read.c: Remove includes.
+
 2019-10-13  Simon Marchi  <simon.marchi@polymtl.ca>
 
 	* ui-out.c (ui_out::call_do_message): Silence

gdb/dwarf2read.c

@@ -41,7 +41,6 @@
 #include "buildsym.h"
 #include "demangle.h"
 #include "gdb-demangle.h"
-#include "expression.h"
 #include "filenames.h"	/* for DOSish file names */
 #include "macrotab.h"
 #include "language.h"
@@ -56,38 +55,27 @@
 #include "addrmap.h"
 #include "typeprint.h"
 #include "psympriv.h"
-#include <sys/stat.h>
-#include "completer.h"
 #include "gdbsupport/vec.h"
 #include "c-lang.h"
 #include "go-lang.h"
 #include "valprint.h"
 #include "gdbcore.h" /* for gnutarget */
 #include "gdb/gdb-index.h"
-#include <ctype.h>
 #include "gdb_bfd.h"
 #include "f-lang.h"
 #include "source.h"
-#include "gdbsupport/filestuff.h"
 #include "build-id.h"
 #include "namespace.h"
-#include "gdbsupport/gdb_unlinker.h"
 #include "gdbsupport/function-view.h"
 #include "gdbsupport/gdb_optional.h"
 #include "gdbsupport/underlying.h"
-#include "gdbsupport/byte-vector.h"
 #include "gdbsupport/hash_enum.h"
 #include "filename-seen-cache.h"
 #include "producer.h"
 #include <fcntl.h>
-#include <sys/types.h>
 #include <algorithm>
-#include <unordered_set>
 #include <unordered_map>
 #include "gdbsupport/selftest.h"
-#include <cmath>
-#include <set>
-#include <forward_list>
 #include "rust-lang.h"
 #include "gdbsupport/pathstuff.h"