Fix compiling GLSL shaders under Windows.

Now the `sed` command cope with files using Windows-style line endings.

Makefile

@@ -1183,7 +1183,7 @@ define DO_REF_STR
 $(echo_cmd) "REF_STR $<"
 $(Q)rm -f $@
 $(Q)echo "const char *fallbackShader_$(notdir $(basename $<)) =" >> $@
-$(Q)cat $< | sed 's/^/\"/;s/$$/\\n\"/' >> $@
+$(Q)cat $< | sed -e 's/^/\"/;s/$$/\\n\"/' -e 's/\r//g' >> $@
 $(Q)echo ";" >> $@
 endef