[clang] [compiler-rt] [libcxx] [cmake] Add hexagon-linux cmake cache files (PR #98712)

[Brian Cain via cfe-commits]

================
@@ -0,0 +1,25 @@
+
----------------
androm3da wrote:

Absolutely.  That's been the status quo and this PR on its own can't change that.

The intent of this pull req is to allow anyone to build a toolchain for targeting hexagon (of which libc++, libc++abi, libunwind are a part).  But another benefit can be that we should be able to setup CI job(s) leveraging this, indeed.  We can enable regression tests for the entire toolchain including compiler, linker *and* target libraries.

https://github.com/llvm/llvm-project/pull/98712