[clang-tidy] performance-inefficient-vector-operation: Support proto repeated field

Summary:
Finds calls that add element to protobuf repeated field in a loop
without calling Reserve() before the loop. Calling Reserve() first can avoid
unnecessary memory reallocations.

A new option EnableProto is added to guard this feature.

Patch by Cong Liu!

Reviewers: gribozavr, alexfh, hokein, aaron.ballman

Reviewed By: hokein

Subscribers: lebedev.ri, xazax.hun, Eugene.Zelenko, cfe-commits

Tags: #clang, #clang-tools-extra

Differential Revision: https://reviews.llvm.org/D67135

llvm-svn: 371963