Implement --enable-gprof option in configure script.
diff --git a/lib/Makefile.am b/lib/Makefile.am
index facb563..b34d544 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -32,4 +32,6 @@
 noinst_HEADERS = fixedsizehash.h system.h dynamicsizehash.h list.h
 EXTRA_DIST = dynamicsizehash.c
 
+if !GPROF
 xmalloc_CFLAGS = -ffunction-sections
+endif