Remove unused include from Profile Mode header

	* include/profile/base.h: Remove unused header that leads to header
	cycle in C++17 mode.

From-SVN: r244449

libstdc++-v3/ChangeLog

 2017-01-13  Jonathan Wakely  <jwakely@redhat.com>
 
+	* include/profile/base.h: Remove unused header that leads to header
+	cycle in C++17 mode.
+
 	PR libstdc++/79075
 	* include/bits/basic_string.h [_GLIBCXX_USE_CXX11_ABI] (basic_string):
 	Make _If_sv private.

libstdc++-v3/include/profile/base.h

@@ -31,7 +31,6 @@
 #ifndef _GLIBCXX_PROFILE_BASE_H
 #define _GLIBCXX_PROFILE_BASE_H 1
 
-#include <functional>
 #include <profile/impl/profiler.h>
 
 // Profiling mode namespaces.