thrift ktls loadgen build

These are a set of scripts perform an OSS build of fbthrift's perf tools, specifically a version of loadgen that uses kTLS.

Instructions

• Drop necessary OpenSSL patches in ./openssl/patches/
• Kernel should be v4.18+ or a kernel with KTLS RX support
• Run ./setup-fbcode-oss-ubuntu-18.04.sh in an Ubuntu 18.04 environment.
  • The environment variable FBCODE_PREFIX controls where supporting libraries will be installed.
  • Example: running env FBCODE_PREFIX=/fbcode ./setup-fbcode-oss-ubuntu-18.04 will install the final loadgen tool in /fbcode/bin/loadgen