错误如下：
gcc is unable to create an executable file.
If gcc is a cross-compiler, use the --enable-cross-compile option.
Only do this if you know what cross compiling means.
C compiler test failed.
网上也没找到资料。后来发现错误是extra-cflags/extra-ldflags写错了。正确写法是：
./configure \
--prefix=${DEST_LIB_DIR} \
--extra-cflags=-I${DEST_LIB_DIR}/include \
--extra-cflags=-I${DEST_LIB_DIR}/include/freetype2 \
--extra-ldflags=-L${DEST_LIB_DIR}/lib \
