【gdb】stdio.h not found error

参考https://github.com/frida/frida/issues/338

主要是/usr/include目录没有，gdb安装时会寻找这个目录，普通xcode-select --install 也并没有产生这个目录。
解决办法：Install the package at
/Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14. pkg
具体操作：cd /Library/Developer/CommandLineTools/Packages/
open macOS_SDK_headers_for_macOS_10.14.pkg