[Makefile] always use $(MAKE) in rules

Required for gmake to work on FreeBSD. (see #6146)

Makefile

@@ -97,7 +97,7 @@ NATIVE_LIBS=-thread -cclib libs/extc/extc_stubs.o -cclib libs/extc/process_stubs
 all: libs haxe tools
 
 libs:
-	$(foreach lib,$(EXTLIB_LIBS),make -C libs/$(lib) $(TARGET_FLAG) &&) true
+	$(foreach lib,$(EXTLIB_LIBS),$(MAKE) -C libs/$(lib) $(TARGET_FLAG) &&) true
 
 copy_output_files:
 	mkdir -p _build
@@ -209,7 +209,7 @@ deploy_doc:
 clean: clean_libs clean_haxe clean_tools clean_package
 
 clean_libs:
-	$(foreach lib,$(EXTLIB_LIBS),make -C libs/$(lib) clean &&) true
+	$(foreach lib,$(EXTLIB_LIBS),$(MAKE) -C libs/$(lib) clean &&) true
 
 clean_haxe:
 	rm -f -r _build $(OUTPUT)
@@ -228,4 +228,4 @@ clean_package:
 .ml.cmo:
 	$(CC_CMD)
 
-.PHONY: haxe libs haxelib
+.PHONY: haxe libs haxelib

libs

@@ -1 +1 @@
-Subproject commit ea953db15a552e682b8dea83e7c98da343ae1d65
+Subproject commit 8841ac89ae9e14b111534c0f1bcbd7715208e3f0