Remove hardcoded optimizations.

Index: Makefile.am
--- Makefile.am.orig
+++ Makefile.am
@@ -27,7 +27,7 @@ endif
 
 # Set flags for gcc.
 if IS_GCC
-CFLAGS += -std=gnu99 -O2
+CFLAGS += -std=gnu99
 if IS_DEBUG
 CFLAGS += -g
 CFLAGS += -Wno-long-long -Wall -W -Wnested-externs -Wformat=2