Add a new clang-tidy check for cert-msc50-cpp (and cert-msc30-c) that...

Add a new clang-tidy check for cert-msc50-cpp (and cert-msc30-c) that corresponds to the CERT C++ secure coding rule: https://www.securecoding.cert.org/confluence/display/cplusplus/MSC50-CPP.+Do+not+use+std%3A%3Arand%28%29+for+generating+pseudorandom+numbers

Patch by Benedek Kiss

llvm-svn: 285809