Commit a945037e8fd0c30e250a62211469eea6765a36ae moved the printing of the "PLEASE submit a bug report" message to the crash handler, but that means we don't print it when forcing a crash using FORCE_CLANG_DIAGNOSTICS_CRASH. Fix this by adding a function to get the bug report message and printing it when forcing a crash. Differential Revision: https://reviews.llvm.org/D81672