[lldb/cmake] Normalize use of HAVE_LIBCOMPRESSION (#135528)
I *think* this was the reason behind the failures in
2fd860c1f559c0b0be66cc000e38270a04d0a1a3: the clang include tool showed
the Config.h headers as unused, and because the macro was referenced
through an `#ifdef`, its removal didn't cause build failures. Switching
to `#cmakedefine01` + `#if` should make sure this does not happen again.
According to D48977, the `#ifndef`+`#cmakedefine` patterns is due to
some files redefining the macro themselves. I no longer see any such
files in the source tree (there also were no files like that in the
source tree at the revision mentioned, but the macro *was* defined in
the hand-maintained XCode project we had at the time).
llvm-project
a22ad659 - [lldb/cmake] Normalize use of HAVE_LIBCOMPRESSION (#135528)
