[clang] [profile] Add a clang option -fprofile-continuous that enables continuous instrumentation profiling mode (PR #124353)

[Wael Yehia via cfe-commits]

w2yehia wrote:

> LLVM Buildbot has detected a new failure on builder `clang-m68k-linux-cross` running on `suse-gary-m68k-cross` while building `clang` at step 4 "build stage 1".

Unrelated or noise. That buildbot had the exact failure few drivers [earlier](https://lab.llvm.org/buildbot/#/builders/27/builds/5835/steps/4/logs/stdio).

https://github.com/llvm/llvm-project/pull/124353