[clang-tidy] readability-non-const-parameter: add new check that warns when...

[clang-tidy] readability-non-const-parameter: add new check that warns when function parameters should be const

The check will warn when the constness will make the function interface safer.

Reviewers: alexfh

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D15332

llvm-svn: 279507