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/Make_morph.mak b/src/Make_morph.mak
index 1eb5ff5..7bd39fa 100644
--- a/src/Make_morph.mak
+++ b/src/Make_morph.mak
@@ -69,6 +69,7 @@
 	option.c						\
 	os_amiga.c						\
 	popupmnu.c						\
+	profiler.c						\
 	quickfix.c						\
 	regexp.c						\
 	screen.c						\