Always rebuild minilua to work around issue #999

This ensures that minilua will always be rebuild. This fixes bug #999,
though we may find a better solution.

We declare ALWAYS_REBUILD as a target, and use the .PHONY property to
designate that it's not an actual file (though it's unlikely that file
would exist on the users computer). While we're there, also add all the
other phony rules like 'install' 'clean' 'lib' etc. as .PHONY so the
rules won't break if those files happen to exist in that folder.

build/Makefile.in

@@ -494,9 +494,13 @@ DYNASM_SCRIPTS = 3rdparty/dynasm/dynasm.lua 3rdparty/dynasm/dasm_x86.lua
 DYNASM_HEADERS = 3rdparty/dynasm/dasm_proto.h 3rdparty/dynasm/dasm_x86.h
 
 .SUFFIXES: .c @obj@ .i @asm@ .dasc .expr .tile .h
+.PHONY: clean realclean install ALWAYS_REBUILD lib all help test reconfig clangcheck gcccheck libuv tracing cgoto switch no-tracing no-cgoto distclean release sandwich
 
 all: moar@exe@ pkgconfig/moar.pc
 
+# Empty target, just in case our make doesn't support the .PHONY property
+ALWAYS_REBUILD:
+
 install: all
 	$(MKPATH) "$(DESTDIR)$(BINDIR)"
 	$(CP) moar@exe@ "$(DESTDIR)$(BINDIR)"
@@ -618,7 +622,8 @@ src/strings/unicode.c: src/strings/unicode_db.c src/strings/unicode_uca.c src/st
 	$(MSG) generating $@
 	$(CMD) $(CAT) src/strings/unicode_db.c src/strings/unicode_uca.c src/strings/unicode_ops.c > $@ $(NOERR)
 
-$(MINILUA): 3rdparty/dynasm/minilua.c
+# Always rebuild minilua to workaround issue #999
+$(MINILUA): ALWAYS_REBUILD 3rdparty/dynasm/minilua.c
 	$(CC) $(CFLAGS) $(LDFLAGS) 3rdparty/dynasm/minilua.c -o $@ $(LDLIBS)
 
 .dasc.c: