$(foreach P,$(WITH_BOOTSTRAPPING_COMPILER),with-bootstrapping-compiler.$P): \
with-bootstrapping-compiler.%:
$(MAKE) -C $* with-bootstrapping-compiler
$(foreach P,$(WITH_BOOTSTRAPPING_COMPILER),with-bootstrapping-compiler.$P): \
with-bootstrapping-compiler.%:
$(MAKE) -C $* with-bootstrapping-compiler