Split-off large-file support flags to TARGET_LFSFLAGS.

src/Makefile

@@ -211,7 +211,8 @@ TARGET_DLLNAME= lua$(NODOTABIVER).dll
 TARGET_XSHLDFLAGS= -shared -fPIC -Wl,-soname,$(TARGET_SONAME)
 TARGET_DYNXLDOPTS=
 
-TARGET_XCFLAGS= -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE -U_FORTIFY_SOURCE
+TARGET_LFSFLAGS= -D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE
+TARGET_XCFLAGS= $(TARGET_LFSFLAGS) -U_FORTIFY_SOURCE
 TARGET_XLDFLAGS=
 TARGET_XLIBS= -lm
 TARGET_TCFLAGS= $(CCOPTIONS) $(TARGET_XCFLAGS) $(TARGET_FLAGS) $(TARGET_CFLAGS)