I have a created a new check for clang tidy: misc-string-compare. This will check for incorrect usage of std::string::compare when used to check equality or inequality of string instead of the string equality or inequality operators.
Example:
```
std::string str1, str2;
if (str1.compare(str2)) {
}
```
Reviewers: hokein, aaron.ballman, alexfh, malcolm.parsons
Subscribers: xazax.hun, Eugene.Zelenko, cfe-commits, malcolm.parsons, Prazek, mgorny, JDevlieghere
Differential Revision: https://reviews.llvm.org/D27210
llvm-svn: 290747