add fbcode_builder manifest
add fbcode_builder manifest

Summary: Add a manifest and CMakeLists.txt for building fb303 with cmake.

Reviewed By: wez

Differential Revision: D15480895

fbshipit-source-id: d47f6ef9b9383b79b31a6170c7d4c9e8337de4d8

facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst,facebookincubator/mvfst