[22feb2024] mystery lsp complaints for iostream headers

1. Setup

working on bespoke streambuf implementation (cmake-examples/zstream/include/zstream/zstreambuf.hpp) See https://github.com/Rconybea/cmake-examples.git

getting mysterious errors from flymake + emacs, e.g. message "<fstream> not found"

Had discarded cmake-examples/build directory, using cmake-examples/.build instead. This was to prevent build tree showing up when running tree in the cmake-examples directory
Left cmake-examples/compile_commands.json as a broken symlink referring to old build directory
This causes lsp understanding of compiler invocation to deteriorate as project acquires new files
Fix by swinging symlink to cmake-examples/.build/compile_commands.json, duh!