build: ensure .lolfx.cpp files get cleaned up.

src/Makefile.am

@@ -50,6 +50,8 @@ nodist_liblol_a_SOURCES = \
     gpu/emptymaterial.lolfx.cpp
 liblol_a_CPPFLAGS = @LOL_CFLAGS@
 
+CLEANFILES = $(filter %.lolfx.cpp, $(SOURCES))
+
 SUFFIXES = .lolfx
 %.lolfx.cpp: %.lolfx
 	echo "/* This file was autogenerated. DO NOT MODIFY IT. */" > $@.tmp

test/tutorial/Makefile.am

@@ -8,7 +8,8 @@ all-local: $(noinst_PROGRAMS)
 
 CLEANFILES = $(noinst_PROGRAMS:%$(EXEEXT)=%.self) \
              $(noinst_PROGRAMS:%$(EXEEXT)=%.elf) \
-             $(noinst_PROGRAMS:%$(EXEEXT)=%.exe)
+             $(noinst_PROGRAMS:%$(EXEEXT)=%.exe) \
+             $(filter %.lolfx.cpp, $(SOURCES))
 
 SUFFIXES = .lolfx
 %.lolfx.cpp: %.lolfx