patch 8.1.1684: profiling functionality is spread out

Problem:    Profiling functionality is spread out.
Solution:   Put profiling functionality in profiling.c. (Yegappan Lakshmanan,
            closes #4666)
diff --git a/src/proto.h b/src/proto.h
index 1c37bfa..9119a52 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -171,6 +171,9 @@
 # include "ops.pro"
 # include "option.pro"
 # include "popupmnu.pro"
+# if defined(FEAT_PROFILE) || defined(FEAT_RELTIME)
+# include "profiler.pro"
+# endif
 # ifdef FEAT_QUICKFIX
 #  include "quickfix.pro"
 # endif