[compiler-rt] [clang-tools-extra] [clang] [PGO] Reland PGO's Counter Reset and File Dumping APIs #76471 (PR #78285)

[Rainer Orth via cfe-commits]

rorth wrote:

This patch broke both the [Solaris/sparcv9](https://lab.llvm.org/buildbot/#/builders/72/builds/2015) and [Solaris/amd64](https://lab.llvm.org/staging/#/builders/94/builds/394) buildbots.

If it really requires recent `lld`, this is guaranteed to not work: `lld` hasn't even been ported to Solaris.  Similar issues most likely will exist on other targets where the bot either doesn't build `lld` or it isn't supported at all.

https://github.com/llvm/llvm-project/pull/78285