Enable -O2 globally

Author: jiegec

build-hnp/utils/Makefrag

@@ -11,6 +11,6 @@ export LD := $(OHOS_SDK_HOME)/native/llvm/bin/ld.lld
 export AR := $(OHOS_SDK_HOME)/native/llvm/bin/llvm-ar
 export RANLIB := $(OHOS_SDK_HOME)/native/llvm/bin/llvm-ranlib
 export STRIP := $(OHOS_SDK_HOME)/native/llvm/bin/llvm-strip
-export CFLAGS := -I$(shell pwd)/../sysroot/include -Wno-int-conversion
-export CXXFLAGS := -I$(shell pwd)/../sysroot/include
+export CFLAGS := -I$(shell pwd)/../sysroot/include -Wno-int-conversion -O2
+export CXXFLAGS := -I$(shell pwd)/../sysroot/include -O2
 export LDFLAGS := -L$(shell pwd)/../sysroot/lib