Mark certain targets as .PHONY in Makefile

[citizen428]

To quote the fine manual:

A phony target is one that is not really the name of a file; rather it is just a name for a recipe to be executed when you make an explicit request. There are two reasons to use a phony target: to avoid a conflict with a file of the same name, and to improve performance.

Note: While you can also declare all .PHONY targets in a list, I've found that individual declarations work better for larger Makefiles like this one, since they require less vertical scanning.

[citizen428]

I should have added that this is relevant for at least one existing target:

Without .PHONY: wasm

❯ make wasm
make: 'wasm' is up to date.

With .PHONY: wasm:

❯ make wasm
cd wasm && make
make[1]: Entering directory '/Users/me/src/herb/wasm'
...