straight--build-compile: add package dependencies to load path (#685)
straight--build-compile: add package dependencies to load path (#685)

Now that we're compiling in a child process, we need to add a package's
dependencies to the load-path prior to compiling. Otherwise macro definitions
defined in a dependency may not be present at compile time and result
in runtime errors.

See: #684
raxod502/straight.el,raxod502/straight.el