Hi all,

Here some small improvements for the compiler/Makefile.

• The Makefile now defines variables for directory paths and build types to improve readability and maintainability.
• The default number of jobs to run in parallel is now based on the available CPU cores, which should improve build times.
• The default target has been set using the .DEFAULT_GOAL directive, so it's not necessary to specify the target on the command line.
• The phony targets have been declared explicitly using the .PHONY directive, which is considered good practice.
• The configure step for tcc is now a separate target that can be invoked independently, which may help with debugging or development.
• The Makefile now uses $(MAKE) instead of hardcoded make to improve portability.
• The CMAKE_GENERATOR option is now passed explicitly to the wla target, which was previously hardcoded in the command line.
• The wla-install target now copies the binaries directly from the wla-dx/binaries directory instead of invoking make again, which should save some time.

Note: the nproc command is available on macOS systems. However, if it is not installed, you can install it using Homebrew by running the following command: brew install coreutils

Overall, these changes should make the Makefile more robust and efficient, while also improving its readability and maintainability.