Summary:
The "performance-inefficient-vector-operation" check finds vector oprations in
for-loop statements which may cause multiple memory reallocations.
This is the first version, only detects typical for-loop:
```
std::vector<int> v;
for (int i = 0; i < n; ++i) {
v.push_back(i);
}
// or
for (int i = 0; i < v2.size(); ++i) {
v.push_back(v2[i]);
}
```
We can extend it to handle more cases like for-range loop in the future.
Reviewers: alexfh, aaron.ballman
Reviewed By: aaron.ballman
Subscribers: zaks.anna, Eugene.Zelenko, mgorny, cfe-commits, djasper
Differential Revision: https://reviews.llvm.org/D31757
llvm-svn: 300534
Haojian Wu